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A website page from Project Cece entitled "Leather vs. Vegan Leather: What's Actually More Sustainable?"

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A website page from Project Cece entitled "Leather vs. Vegan Leather: What's Actually More Sustainable?"

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With ethical fashion, things aren't always black and white. So, no: the real leather vs vegan leather debate isn't as simple as "leather = bad, vegan leather good".

Here's an objective, jargon-free comparison to help you make an informed decision.

Real leather and sustainability

Leather comes from the tanning of animal skins and hides, from cattle to sheep and even aquatic animals like alligators.

Eco-friendly pros of real leather

Most leather is a by-product of the meat industry, so it actually reduces waste. If the leftover hides were sent to landfills, this would generate higher carbon emissions

Naturally biodegradable

Durable: when cared for, real leather can last you for decades (again, less waste)

Sustainability cons of real leather

It relies on livestock: this is the world's largest user of agricultural resources and lands and one of the main causes of deforestation, which leads to biodiversity loss and further contributes to climate change

Leather tanning and dyeing are chemical-heavy processes: this is bad for the environment (especially when these chemicals pollute water resources), workers, and the wearers themselves, in some cases. Vegetable tanning is a more sustainable option but, sadly, not widely used

Not all leather is a by-product! Plus, it actively contributes to 10% of the animal's total value

This reinforces the main ethical problem behind leather: that animals have to die for it, whether more or less directly

Vegan leather and sustainability

Also known as faux leather or, in some cases, pleather (plastic leather), vegan leather is usually made from polyvinyl chloride (PVC) or polyurethane (PU).

Eco-friendly pros of vegan leather

No livestock involved: the main advantage of vegan leather vs real leather is that the former doesn't contribute to the excessive use of agricultural lands, deforestation, and animal deaths

It has lower carbon emissions: 15.8 kg per square metre of vegan leather vs 17.0 for leather

In some cases, it involves recycled plastic or bypasses this material altogether. In fact, some vegan leather is made from natural options like pineapple leaves, apple peels, or cork

Sustainability cons of vegan leather

Its production also tends to be chemical-heavy. PVC, in particular, is extremely polluting and releases hazardous dioxins. PU is the lesser of the two evils, but still derived from fossil fuels

Not biodegradable or, with natural options, only partly. Because vegan leather releases phthalates and toxic particles when decomposing, it can affect the environment and even the health of animals

It tends to be less durable than real leather, so it leads to additional waste when you replace it

Real leather vs vegan leather: so, is vegan leather better for the environment?

Vegan leather isn't automatically better for the environment. Our honest answer is... it depends!

For example, the environmental impact of purchasing one real leather piece tends to be lower than that of replacing faux leather products every few years.

So, the answer to the leather vs vegan leather debate really depends on how that item was produced, how you use it, and what matters the most to you personally.

From a sustainability point of view:

consider sticking to the most eco-friendly real leather that'll last you for many years. This should be an actual by-product and, if possible, made with vegetable tanning rather than chemicals

as for vegan leather, choose PU over PVC or, even better, natural options

From an ethical standpoint, however, vegan leather is a more logical choice than real leather. It's also suitable for vegetarians and vegans.

You can browse both real leather and vegan leather items from different fairtrade brands on Project Cece. And, if you've found this comparison helpful, start receiving our tips and inspiration to make more ethical fashion choices.

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Leather vs Vegan Leather: What's ACTUALLY More Sustainable? | Sustainable Fashion Blog| Project Cece

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Bad news: it’s not a one-word answer. Good news? We’ve created a simple real leather vs vegan leather comparison to help you make the right choice for YOU.

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A blog post from Nomomente entitled "Faux Leather vs Real Leather: Which One is More Eco Friendly?"

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A blog post from Nomomente entitled "Faux Leather vs Real Leather: Which One is More Eco Friendly?"

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1) The demand for leather is growing. Over 22 billion square feet of leather is produced every year, roughly equivalent to the size of a small country. By 2030, it is estimated to reach just under 30 billion square feet per year. As more and more people consume leather products, the question of which one has a greater impact on the environment, real leather vs fake, becomes very important.

2) Sustainability is increasingly important to consumers. The 2019 Pulse of the Fashion Industry report found that consumer concern for sustainability is growing. More than a third of survey respondents reported that they had "already switched from their preferred brand to another for reasons related to responsible practices," while over half said that their next purchase would be based on sustainability criteria.

"For the first time, this data confirms that most consumers include sustainability considerations in their decision-making framework."

First Things First: Let's Get Some Terminology Straight

What's faux leather? This is an imitation product, made to look and feel like leather, and created as a leather alternative in the production of typically leather-based products, like handbags, purses, jackets, watches, upholstery and shoes. It is made of fabric coated with a plastic polymer (polyurethane (PU) or polyvinylchloride (PVC)). (For those wondering, is PU leather faux leather , the answer is yes.)

What is real leather? Real leather means leather. It is the genuine article - a raw material manufactured from the hides of animals, used in the production of commercial goods like clothing (leather shoes and jackets), accessories (leather bags, watches, wallets) and home goods (leather chairs and sofas, and car interiors).

Quick facts: Is faux leather real leather? No. Real leather is made from animal hides, while faux leather is made from plastic-coated fabric.

Bonded leather is like a mix of real leather and faux leather combined. The difference between faux leather and bonded leather is that while faux leather is 100% animal-free, bonded leather contains 10-20% animal hide. It is therefore decidedly vegan.

Sustainability Factors for Comparing Faux Leather Versus Real Leather

Quick facts : Is faux leather bad? There are many variables to weigh when comparing vegan leather vs real leather, and hard to say whether one or the other is truly "bad".

1) The demand for leather is growing. Over 22 billion square feet of leather is produced every year, roughly equivalent to the size of a small country. By 2030, it is estimated to reach just under 30 billion square feet per year. As more and more people consume leather products, the question of which one has a greater impact on the environment, real leather vs fake, becomes very important.

2) Sustainability is increasingly important to consumers. The 2019 Pulse of the Fashion Industry report found that consumer concern for sustainability is growing. More than a third of survey respondents reported that they had "already switched from their preferred brand to another for reasons related to responsible practices," while over half said that their next purchase would be based on sustainability criteria.

"For the first time, this data confirms that most consumers include sustainability considerations in their decision-making framework."

First Things First: Let's Get Some Terminology Straight

What's faux leather? This is an imitation product, made to look and feel like leather, and created as a leather alternative in the production of typically leather-based products, like handbags, purses, jackets, watches, upholstery and shoes. It is made of fabric coated with a plastic polymer (polyurethane (PU) or polyvinylchloride (PVC)). (For those wondering, is PU leather faux leather , the answer is yes.)

What is real leather? Real leather means leather. It is the genuine article - a raw material manufactured from the hides of animals, used in the production of commercial goods like clothing (leather shoes and jackets), accessories (leather bags, watches, wallets) and home goods (leather chairs and sofas, and car interiors).

Quick facts: Is faux leather real leather? No. Real leather is made from animal hides, while faux leather is made from plastic-coated fabric.

Bonded leather is like a mix of real leather and faux leather combined. The difference between faux leather and bonded leather is that while faux leather is 100% animal-free, bonded leather contains 10-20% animal hide. It is therefore decidedly vegan.

Sustainability Factors for Comparing Faux Leather Versus Real Leather

Quick facts : Is faux leather bad? There are many variables to weigh when comparing vegan leather vs real leather, and hard to say whether one or the other is truly "bad".

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The Great Debate: Faux Leather vs Real Leather, Which One is More Sustainable?

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There's a roaring debate in sustainable fashion: faux leather vs real leather, which one is more eco friendly? We break it down point by point.

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A Harpar Bazaar article entitled "Is vegan leather worse for the environment than real leather?"

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A Harpar Bazaar article entitled "Is vegan leather worse for the environment than real leather?"

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The adoption of Veganuary in the UK alone is expected to have saved the earth's atmosphere from the equivalent production of CO2 as 450,000 flights from London to Berlin, as well as 2.5 millions litres of water, according to a study by a professor at the University of Oxford. This is the impact of just 31 days. A more permanent adoption of veganism would, according to another study from the university, be the "single biggest way" to reduce our environmental impact, lowering an individual's carbon footprint by 73 per cent.

These studies have definitively claimed that a vegan diet is less harmful to our environment than one that contains meat and dairy. This attitude often leads to the assumption that we should be adopting the same approach when it comes to our wardrobes, particularly with leather.

And, with the appetite for more sustainable fashion on the increase (searches are up 75 per cent year on year, according to global fashion search engine ), brands are looking to vegan alternatives in the hope of delivering on this demand. But, are vegan-leather alternatives actually better for our environment than the real thing? We spoke to designers on both sides of the argument to try and discover the most sustainable way to be wearing the material.

What exactly is vegan leather?

Vegan leather is a material that mimics leather, but is created from artificial or plant products instead of animal skins.

It is most often made from two different plastic polymers; polyurethane (PU) and polyvinyl chloride (PVC) - they are most commonly used due to their wrinkled texture which helps to give the effect of real leather, according to PETA.

As well as these synthetic materials, vegan leather can also be made from more natural resources, including pineapple leaves, cork, apple peels, and recycled plastic.

Can vegan leather rival the quality of the real thing?

Despite the raw materials sounding nothing like what goes into real leather products, vegan leather has come on leaps and bounds over the past few decades, meaning that well-made vegan-leather products can often be mistaken for the real thing.

Sandra Sandor, the creative director of Paris Fashion Week label Nanushka, favours vegan leather for her products, many of which are worn and loved by some of the biggest names in fashion.

"The vegan leather we use is buttery soft and it feels like leather, sometimes people mistake it for real leather, so it's definitely not compromising on quality," she tells us. "It has a luxurious touch and we get a lot of compliments on it."

has become a favourite among influencers and fashion editors alike, with many of the label's vegan-leather pieces remaining its most popular styles. The brand is a great example of the potential of using vegan-leather alternatives without compromising on style.

That being said, some designers do see a drawback in the quality of vegan leather for certain products, leading them to use a mix of real and vegan, including London Fashion Week favourite, Rejina Pyo, who uses faux leather for trousers and jackets, but tends to opt for the real thing when it comes to accessories.

"When making shoes or bags, we often use leather because it looks great, feels comfortable and most importantly it's durable," Renee Cuoco, the label's managing director explains. "It wears well over a long period of time."

Part of the reason for this is attached to how the consumers view vegan leather.

"I think for customers there is also still a perception of value attached to leather, and perhaps are more likely to keep and covet leather products over synthetic alternatives.

"We're careful about using the term vegan leather as it can be a bit misleading. Veganism is a commitment to not use any animal-derived material or ingredient, so it makes sense that the term vegan leather is only used by brands who have made the commitment to being 100 per cent vegan."

Other brands are also turning to animal alternatives. Although not vegan, luxury fashion designers such as John Galliano, Prada, Christian Dior, and Louis Vuitton have all sourced fish skin from Atlantic Leather for collections in a bid to lessen the pressure of real leathers. Pineapple leather is used by brands including Hugo Boss on a range of shoes, as well as in H&M's Conscious Exclusive collection - the label also plans to use wine leather in its next Conscious drop. Apple, mushroom, corn and mango are all other animal substitutes used that aren't manufactured with the same toxic chemicals used in leather tanning, Peta tells us.

Is vegan leather more sustainable than real leather?

When assessing the sustainability credentials of vegan leather, we need to look at its raw properties and how its made - not all vegan leather is created equal.

As we've stated, some vegan leather is made from plant-based materials, while others are created from artificial products. Nanushka, for example, uses vegan leather that's polyurethane-based, which is a plastic material. The inclusion of these artificial products can be where sustainability issues arise.

"It's not without environmental concerns," Sandor says. "However there's reasonable ground to state that the environmental impact of producing vegan leather is lower than real leather."

The Environmental Profit & Loss, a sustainability report developed in 2018 by Kering, agrees with Sandor's claim, stating that the impact of vegan-leather production can be up to a third lower than real leather.

"The impact of real leather is driven by land use and GHG emissions associated with animal agriculture," Sandor explains. "The Livestock sector is the world's largest user of agricultural land through grazing and the use of feed crops."

As a result, this plays a major role in climate change, the management of water and biodiversity. For example, the cattle industry in Brazil has been a great driver of deforestation causing biodiversity loss and contributing to climate change.

However, despite vegan alternatives being thought to have a lower impact on the environment than the real thing, it does have clear drawbacks, particularly when it's made from plastic.

Clothing made from plastic can pose a threat during and after its lifespan because it could end up in water or landfill. This takes years to degrade and releases toxic chemicals into the environment, which is unsustainable. "It's estimated that 13 million tonnes of synthetic fibres enter our oceans each year," warns Sandor.

We're aware of the dangers of plastic-based materials once used, but Sandor warns that whilst using the product, its microfibres shed and threaten human health, due to accumulation of micro-plastics in the food chain, as well as absorbing them.

Sustainable designer Jourdan Norcose of Boyish Jeans, explains that designers should be wary about some forms of vegan leather that are more plastic-based.

"Leather is a love-hate story," he tells me frankly. "Vegan leather can be made from plastics which take years to biodegrade, so it's actually worse for the planet than regular."

Micro-plastic pollution is a big threat, as it uses an extensive amount of water, energy and chemicals to be processed and made into the material which sadly impacts the earth.

"People think it's better because it says vegan on it, but that's because people aren't taking the time to really learn about what they're buying."

13 million tonnes of synthetic fibres enter our oceans each year

Greenwashing, when brands use buzzy words to appear more environmentally friendly, is a big part to play in Norcose's point - it is important to do your research on the brands and substitute materials that you're spending your money on, both processes and products.

On one hand, real leather can be a harmful material to work with because of the tanning process. To make the animal skin wearable, this means using lots of energy and chemicals to transform the skin into the leather material we're used to.

"It's the strong chemicals that are used to break down protein in the skin. This can be done with a more natural process as well, but often harsh chemicals are used to speed up the tanning process," explains Nanushka's Sandor.

"The use of heavy metals in the tanning and dyeing process has been a major concern in leather manufacturing, putting at risk the environment through chemicals leaking into water streams, the workers and also the wearer themselves."

If the chemicals find their way into the water, it causes an excessive richness of nutrients that sparks the growth of algae and animal death due to the lack of oxygen in the waters. In extreme cases, workers in the tanneries are exposed to serious health risks such as lung cancer and leukaemia.

As well as dangerous chemicals, producing real leather also damages environments through deforestation.

"The leather industry has been responsible for deforestation in South America," Sandor explains, "which is also a major cause of climate change and biodiversity loss." Deforestation is driven by land use, greenhouse gas emissions from animal agriculture (most farm-related emissions come from methane), grazing and the use of feed crops.

However, not all designers who use real leather are contributing to this issue. At Rejina Pyo, the brand only uses leather from tanneries that are rated by the Leather Working Group, which works to improve traceability across the leather industry.

"We're aware of the negative environmental impacts of the leather industry and how opaque it is, which is why we look for tanneries rated by the Leather Working Group," Cuoco explains.

These tanneries are rated on its energy and water use, emissions and chemical input, as well as having a clear supply chain that traces back to the slaughterhouse.

"There's still a long way to go and it's not a perfect solution but the LWG offers a step in the right direction," Cuoco says.

As well as ensuring a brand has a clear supply chain if you're buying real leather, opting for a brand that uses vegetable tanning as opposed to chemical is less harmful to the planet.

"Leather products treated with natural vegetable tannins are biodegradable and can be easily discarded at the end of their natural life," explains Maj-La Pizzelli, creative director at sustainable accessorise label, ATP Atelier. "Our collections are made from vegetable-tanned Tuscan vachetta leather. For us, this is a conscious choice on so many levels."

The Italian artisan tradition of vegetable tanning has been handed down from generation to generation. "It's beautiful and also supports a more sustainable fashion cycle," Pizzelli notes.

Not only does vegetable-tanned leather does not contain any toxic substance (such as azo-dyes, nickel, PCP or chrome VI) many tanneries reclaim hides from the food industry to prevent waste, which in turn encourages a recycled closed-loop system.

With all of this in mind, whilst buying vegan leather means you're avoiding using animal products, its replacement can sometimes be plastic-based, which is harmful to the environment and takes years to degrade. By opting for real leather, it's not the actual animal skin that's bad for the environment as this is a natural product. However, the chemicals used in the tanning process remains harmful and the fact that the leather industry is contributing to deforestation, so it is better to choose leathers that have been vegetable tanned.

What if the real leather is a by-product?

The obvious disadvantage to buying real leather is you're contributing to animals dying for fashion. Although this can be counteracted by the fact that leather is a by-product of the meat industry, it still remains the same that you're wearing an animal and some people, depending on their personal ethics, would argue that that sends a message.

Faux-fur designer Emma Brewin says it's still unethical to justify using real leather. "I think some people kind of justify buying it because it's a by-product, but that's not how I see it at all," she tells us.

That being said, with more of us wanting to become more sustainable in fashion and beyond, striving to be zero waste is key. So you could, in theory, argue that using animal skin to make leather goods contributes to no waste. Some other materials like furs can be seen as wasteful, as the whole animal might not be used in some cases. In other words, it's simply using up resources.

Some fashion labels adopt this into their designs. Danish brand Saks Potts justifies its use of real leathers in fashion: "Leather is often a by-product from the meat production, which is why many people legalise it more," Catherine Saks explains. "Danish mink are completely zero waste, the fat is used for fuel on Danish busses, the bones are used as feed to other animals and a large amount are used as fertiliser for organic Danish vegetable production."

What leather should I be investing in?

The answer is not black and white - there are strong arguments on both sides. The best option is to do your research as thoroughly as possible on a case by case basis.

If you are thinking of buying vegan leather, look into what alternatives the brand is using and be aware of the detrimental effects of plastic-based products. If you are opting for real leather, read up on the brand's tanning processes to find how they create their pieces and be aware of their ethical processes.

It's not as simple as real leather versus vegan leather, whichever you decide, just make sure to do your research to help you make informed choices. Find out who you're giving your money to and whether it's something you want to support, regardless of the latest trends or aesthetics.
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Is vegan leather worse for the environment than real leather?

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The adoption of Veganuary in the UK alone is expected to have saved the earth's atmosphere from the equivalent production of CO2 as 450,000 flights from London to Berlin, as well as 2.5 millions litres of water, according to a study by a professor at the University of Oxford .

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A journal article from Coatings entitled "Comparison of the Technical Performance of Leather, Artificial Leather, and Trendy Alternatives."

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A journal article from Coatings entitled "Comparison of the Technical Performance of Leather, Artificial Leather, and Trendy Alternatives."

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by * , , and

FILK Freiberg Institute gGmbH, Meißner Ring 1, 09599 Freiberg, Germany

Author to whom correspondence should be addressed.

1. Introduction

A circular economy aims at reusing consumed materials and ideally, product cycles become closed according to the cradle-to-cradle principle [ 1, 2]. "Bio-based" means the use of biogenic raw materials to manufacture a variety of products instead of fossil gas, coal, or petroleum as part of the bioeconomy. Lastly, "biodegradable" means that a material can be degraded in the environment by microorganisms and physicochemical impact. Recently, the societies of the countries of the Global North have experienced a strong change in their mindset due to the discussion about climate change, finiteness of resources, the overutilization of ecosystems, and the pollution of the environment by non-degradable or harmful substances. This affects especially the consumer goods industry and the designers of new materials aim to replace fossil-based polymers with biogenic and fully biodegradable materials while being animal-free and without the use of any harmful substances. Ideally, the new materials are made from domestic waste, sawdust, or organic garbage [ 3, 4, 5].

Leather is a bio-based and biodegradable material with a tradition nearly as long as mankind. For centuries, it was used as a strong and long-lasting material with a broad spectrum of materials properties. Leather was used as protective and decorative clothing for sports goods and as technical material, e.g., for transmission belts, buckets, or as wineskin. Until the middle of the 19th century, leather occupied the materials property gap of a flexible material besides stone, metal, and wood as hard materials and various textiles, which were not waterproof. Processing allowed adjusting the leather properties from a hard board-like appearance, e.g., as sole leather to very soft touch textile-like glove leathers. To manufacture shoes, leather is made hydrophobic, and as wash leather, it absorbs much liquid. The basic structure is an animal skin, which can be described as a non-woven with different density gradients in grain, papillary and reticular layer ( Figure 1 A).

During industrialization, alternative materials were invented, first and foremost the oil clothes made from textiles (linen, cotton), which were soaked or coated with boiled linseed oil and added with fillers, siccatives, and pigments [ 6]. The next level of coating textiles was achieved by the use of natural rubber but only the discovery of vulcanization led to non-sticky films [ 7]. More and more new materials emerged with the invention of additional synthetic polymers, which allowed the replacement of leather in many applications. Synthetic polymers enabled customized and high-performance solutions that outperformed leather by far for technical applications in gears, conveyor belts, or vessels. Alternatives were developed as well in design-driven applications such as upholstery, shoes, and clothing. Often, it is aimed to imitate leather by these materials.

Leather shows a number of unique properties, which are highly valued for purposes such as strength and elasticity, water vapor permeability, abrasion resistance, durability, and longevity. In the past, synthetic materials competing with leather triumphed due to lower prices, they are often easier to be processed and can be manufactured as a continuous material according to industrial needs in roll-to-roll production lines. However, leather is still popular due to its beneficial properties, natural appearance, and a touch of noble material.

Synthetic alternatives usually consist of textile support covered by two or more synthetic polymer layers ( Figure 1 B). Nowadays, often polyester textiles coated by PVC or polyurethane films are used, making them a completely fossil-based material. The surface optic can be designed leather-like by embossing a grain structure. Many different terms are used to describe these materials in the market, e.g., artificial leather, synthetic leather, leatherette, imitation leather, faux leather, man-made leather, bonded leather, pleather, textile leather, or polyurethane (PU)-leather. Meanwhile, the usage of these terms is restricted in the European standard EN 15987. Here, we will use the term "artificial leather" to describe synthetic materials imitating the optical appearance of leather.

In recent years, concerns over sustainability in any field of industrial production have led to a pressing rationale to enhance the use of natural materials and replace non-renewable fossil-based raw materials. Although leather is bio-based and renewable, these considerations did not lead to a renaissance of leather. Instead, leather got even more under pressure due to ongoing discussions over the greenhouse gas emission of cattle breeding, the sustainability of leather production, and animal welfare. At the same time, an increasing number of people want to eat consciously meat-free or to do without any products of animal origin entirely. All these needs pose new challenges in culture and material development [ 3].

One strategy pursues the development of alternative nature-based, animal-free fibrous materials. This material is trama, the bulk material of some mushroom fruitbodies (e.g., Fomes fomentarius, Phellinus ellipsoideus). The extraordinary soft feel of the dry mycelium makes it a precious material for cups and handcraft accessories and already the Ice-man used it as a material in combination with leather [ 8, 9]. Muskin ® is an example of this material. Due to the complicated harvest, the restricted availability of the mentioned fungi, and the limited areas that can be obtained it seems to be far from being able to replace leather.

Further new ways are paved by using biotechnological processes to produce fiber-based materials. Namely, fungi and symbiosis of bacteria and yeast are used to produce fibrous networks aiming to imitate the fibrous structure similar to an animal skin as single materials or as support for a coating layer. Micro-cellulosic fiber networks are produced by bacteria (e.g., Acetobacter xylinum), the mycelium fiber networks of fungi hyphae consist of chitin, cellulose, and proteoglycans [ 5, 10, 11]. These mycelia grow on organic waste [ 11, 12].

In a second strategy, it is tried to reduce the non-renewable content of artificial leather by replacing parts of the synthetic component polyvinylchloride (PVC) or polyurethane (PUR) of synthetic coatings with agricultural waste-derived products as filling material, such as grain, apple pomace (Vegea ®, Appleskin ®), or milled cactus leaves (Desserto ®).

A third way to replace all fossil-based raw materials in a coated textile has been explored in Pinatex ®. Renewable fibers of pineapple leaves are processed into non-woven support coated with polylactic acid (PLA) produced from corn starch [ 13].

Regardless of the type of material, it can be leather, artificial leather, or a trendy alternative a couple of physical and mechanical limits are usually defined and have to be achieved. These limits must be evaluated in regard to the stresses associated with the production, processing, and use of the materials. In general, examinations to qualify materials and to quantify their properties need to be performed according to standardized testing procedures.

Here, we present a comparative study of leather and alternative materials, which are used for similar final applications, focused on material structures, physical, and mechanical performance. Additionally, the materials were screened for hazardous substances by established standardized test methods with respect to shoe, glove, and apparel goods applications. Materials intended for automotive and upholstery applications are explicitly not included in this study, because they have to meet many superior specifications.

We focused on material performance. Other important aspects such as the origin of the raw material (renewable or oil-based), the carbon footprint, the environmental footprint, traceability, and biodegradability are not dealt with in this study. Alternative materials of different sources were tested in comparison to a common shoe-upper leather as a reference and a conventional PUR-coated textile (artificial leather) as used for footwear as a second reference. All materials are commercially available and have already been applied in various types of final products. The materials were tested according to the appropriate internationally harmonized and accepted specifications for shoe, glove, and apparel goods [ 14, 15, 16].

2. Materials and Methods

Nine materials, which are offered as an alternative for leather and represent different principal structures, have been investigated by light microscopy; their physical properties were measured and their chemical compositions were analyzed ( Table 1). The registered trademarks are specified in the table. Additionally, a shoe upper leather and a polyurethane-coated textile as artificial leather were tested as a reference. The Noani ® sample was obtained as a belt consisting of several materials, which had been combined by sewing.

The physical characterization comprised standardized measurements of thickness, tensile strength, tear strength, flex resistance, water vapor absorption, and water vapor permeability [ 17, 18, 19, 20, 21, 22]. The cross sections, surfaces, and the reverse side of the materials were portrayed by light microscopy at different magnifications. Chemical constitution and additives were investigated by FTIR (fourier transform infrared spectroscopy) and thermal desorption GC/MS (gas chromatography/mass spectroscopy). FTIR spectra were measured using a diamond ATR (attenuated total reflection) technique with 16 scans in a range of 4000-650 cm −1. Evaluation of the spectra was based on own and various commercial databases. Volatile and harmful substances were measured according to VDA 278 [ 23] (VDA-Verband der Automobilindustrie, Germany). A total of 5 mg to 10 mg of material were heated to 120 °C for 60 min, and all volatile compounds were collected from the evaporate by cooling with liquid nitrogen to minus 100 °C. The substances were vaporized from the trap for 5 min at 280 °C, separated and characterized by GC/MS (GC: 50 °C for 2 min, 25 K/min to 160 °C, 10 K/min to 280, 10 min at 280 °C, column Ultra 2 (5% phenyl-methylsiloxane), 50 m × 320 µm × 0.52 µm, flow 1.3 mL/min constant pressure, MS: 29-450 m/z).

For evaluation, 10 well-trained panelists assessed the materials to evaluate touch and feel. No material related information was provided to them in advance of the evaluation. The materials were presented to the panelists always in the same order either by laying it directly on a table board or placing it on a soft PUR foam of 4 mm thickness. The surfaces of the materials were blindly touched without any stretching or folding. The touch and feel properties of all materials were referenced to leather-temperature sensation (warmer or colder), deformation in z-direction (softer or harder), roughness, slipperiness/blocking behavior, pleasant or unpleasant, natural or artificial touch, high- or low-quality feeling.

3. Research Results

3.1. Material Composition and Structure

All materials are composed of fibers. However, chemical constitution, arrangement, fiber size, and coating follow different principal concepts. The results of the light microscopic investigations, thermal desorption analysis, and FTIR spectra allow us to identify the compositions of the materials ( Table 1).

A selection of microscopic pictures of the cross sections representing the different principal structures is shown in Figure 2, and the different surface designs are presented in Figure 3. All microscopic pictures are added in high resolution in the supplements as well as an example of a FTIR spectrum of Desserto ®, a PUR coated material (see Supplementary Materials).

The structures of Desserto ® ( Figure 2A), Vegea ®, and Appleskin ® reflect the typical composition of PUR-coated artificial leather used for, e.g., shoe or upholstery application. The support of the investigated samples consisted of knitted or woven polyester textiles, except that of Vegea ®, which was made of cellulose. The textiles were coated with foamed polyurethane-based middle layers containing organic fillers based on cellulose. The materials are finished with polymer-based topcoats. The surfaces of the materials were partly embossed to achieve a leather-like optic and to adjust the haptic ( Figure 3E-H). Even Teak Leaf ® falls into the structural category of a coated textile. Here, the textile support on the reverse side is built by two non-woven layers. The middle layer is cellulose-based, the fibers are stuck together with an acrylic acid-based polymeric binder, and the basic support on the reverse side is polyester-based. On the top, the Teak Leaf ® material is coated by a transparent waxy polyolefin film. The leaf of teak mainly fulfills desired optical needs ( Figure 3 D).

Pinatex ® ( Figure 2D) and SnapPap ® consist of a cellulose-based fibrous non-woven. The fibers of SnapPap ® are bonded by an acrylic acid-based polymeric binder. In contrast, the investigated sample of Pinatex ® is coated with a thin polymeric layer. The fibrous structures of the non-woven fabric of both materials are visible at the surface due to the thin coating layer ( Figure 3 I,K).

Muskin ® ( Figure 2B) and Kombucha are single-layer materials without any textile support and without a topcoat. Both consist of polysaccharides. Muskin ® appears very porous composed of fine brown fibers with a fiber orientation perpendicular to the surface. These fibers appear at the surface as a fine lawn without a distinct structure ( Figure 3B). In contrast, Kombucha consists of one compact layer, which contains some inclusions and talcum and shows a glossy brown surface ( Figure 3 C).

It was found that Noani ® was not a single material but crafted of three distinct layers. The top is formed by an embossed microfiber material, the middle layer consists of leather board material and the backside is a PUR/PVC-coated textile that consists of three layers typical for conventional artificial leather. The use of a leather board material is surprising because Noani ® is referred to as a vegan product and the label "PETA approved" is embossed in the material. Because of this and since the Noani ® sample does not represent a single material, it will not be further discussed with respect to structural categories. Regardless of the actual composition, all engineered materials try to mimic a natural appearance ( Figure 3).

3.2. Touch and Feel Properties

The surface of Muskin ® and the upper material of Noani ® feel pleasant. Due to the presence of very fine fibers, both materials create a velvety feeling similar to suede leather. The materials with synthetic surfaces as in artificial leathers (Desserto ®, Appleskin ®, Vegea ®, PUR-coated textile) show a soft feeling and can be deformed in the z-direction. However, the touch of these materials appears artificially with a sticky tendency. The surface of Pinatex ® and Teak Leaf ® appears synthetic, too. In addition, Desserto ®, Pinatex ®, and SnapPap ® are evaluated to feel rough. The surface of Kombucha appeared sticky.

3.3. Thickness

The thickness of the materials was determined by surveying the prepared microscopic cross sections. The overall thickness of all materials was found to range from 0.29 mm to 6.22 mm, which also shows the variety of the material types ( Table 2). The thickness of leather, the PUR-coated textile, and the trendy alternatives Desserto ®, Appleskin ®, Vegea ®, and Pinatex ® are in a typical range for materials used for shoes, gloves, and apparel goods applications. The materials Kombucha, SnapPap ®, and Teak Leaf ® appear very thin and in contrast, Muskin ® is very thick for the mentioned applications. In consequence, already from the results of the thickness measurements, significant differences in the material properties could be expected, e.g., in deformation properties.

3.4. Tensile Strength and Tear Strength

The most important mechanical properties for materials used for shoes, gloves, and apparel goods are tensile strength and tear strength [ 17, 18]. The results for both parameters vary over a very wide range, whereas the category of naturally grown tissues shows the broadest range.

Leather as the grown skin tissue shows a very high mechanical stability (tensile strength, tear strength), representing the highest value for the tensile strength and tear strength within that survey. Tensile strength exceeds the specification of >15 N/mm ² for chrome tanned upper leather for shoes (ISO 20942) [ 14]. In contrast, the values of the Muskin ® sample are extremely low.

The coated textiles show tensile strengths of 9 up to 20 N/mm ². The tensile strength of coated textiles depends mainly on the properties of the supporting fabric. The results show a reasonable choice of fabric for the intended use of these engineered materials regardless of the natural or artificial origin of the fabric fibers.

The tensile strengths of the non-woven materials made of natural plant fibers range from 4 up to 25 N/mm ². Strength depends on fiber properties and fiber bonding. Despite a satisfying tensile strength, the tear resistance of SnapPap ® is low due to the short fiber length, which cannot be leveraged by the polymeric binder. Except for the non-woven materials, tear strength follows the same tendency as tensile strength.

3.5. Flex Resistance

Materials for shoes must resist intensive bending and convex and concave deformation during usage. The flexometer test is used to assess the long-time resistance against bending. Grade 0 is the best rating indicating that the material itself and the coating layers shows no cracks by flexing. A grade of ≤2 (only very small cracks in top layer of the coating) is usually accepted to pass that test. When a grade of >2 is observed, flexing has to be stopped and the number of flex cycles is noted. Leather, Pinatex ®, and PUR-coated textile fulfilled the specification of >80.000 flex cycles according to ISO 20942. The flex resistance of Teak Leaf ®, SnapPap ®, and Muskin ® material was found to be insufficient for the aimed applications.

3.6. Water Vapor Permeability and Water Vapor Absorption

A pleasant wearing comfort of shoes, gloves, or apparel is related to the water vapor permeability (WVP) of the material, which allows transporting the humidity of the body through the clothing material to its surface. The comfort is also enhanced by the ability of the materials to absorb water vapor. Comfortable water vapor permeability limits are specified in ISO 20942 to be >>0.8 mg/(cm ² × h). Leather, Muskin ®, and SnapPap ® exceed the water vapor permeability by far, and Pinatex ® and PUR-coated textile still fulfill the ISO 20942 requirement. The WVP of all other materials is insufficient.

Water vapor absorption (WVA) of Kombucha, leather, and Muskin ® is high, presumably due to their polar nature of the natural polymers. The other materials, especially those that contain a significant amount of synthetic polymer with less polarity show much lower water vapor absorption.

3.7. Harmful Substances

The materials were examined for potentially hazardous substances by means of thermal desorption analysis. In several samples (Appleskin ®, Pinatex ®, Desserto ®, Vegea ®, SnapPap ®, Teak Leaf ®) synthetic and biogenic raw materials had been combined. However, the processing of fossil-based raw materials often requires the application of solvents, crosslinking agents, or plasticizers to achieve suitable material properties.

All tested materials emitted volatile organic compounds when applied to the thermal desorption screening procedure. Restricted substances were identified in the samples of PUR-coated textile (reference), the similarly constructed materials Desserto ®, Appleskin ®, and Vegea ®, but also in Pinatex ®. The PUR-coated textile contained considerable amounts of dimethylformamide (DMFa) and toluene and traces of N,N-dimethylacetamide. In Appleskin ®, butanone oxime and traces of DMFa were detected. Desserto ® contained the five restricted substances butanone oxime, toluene, free isocyanate, folpet (an organic pesticide), and traces of the plasticizer Diisobutyl phthalate (DIBP). Toluene was detected in the sample of Vegea ® and DIBP in that of Pinatex ®.

4. Discussion

The materials that have been tested in this study are used to manufacture fashionable consumer goods as shoes, bags, clothes, and accessories. In this regard, aspects of (1) functional properties and (2) the appearance have to be discussed. While the construction of the material mainly influences the functional properties, the appearance is markedly a result of the surface properties. Both groups of properties varied on a very broad scale, though the materials are offered for similar final applications. Analyzing the composition, the construction, the surfaces, and the feel allowed us to compare the materials in regard to their possible performance. For this purpose, the materials were investigated by standardized testing procedures for leather since the materials are offered as a leather alternative.

4.1. Structure

Based on the structural design and with respect to functional properties, the investigated samples can be grouped into three completely different material concepts, which are (a) grown animal-free materials, (b) multi-layered coated fabrics as for artificial leather combined with plant-based additives, and (c) non-woven fabrics with or without a surface finish.

As derived from the results of the FTIR analysis, the functional layers of the coated fabrics are mainly PUR based. In contrast, fully bio-based naturally grown materials investigated in this study did not nearly fulfill the mechanical requirements expected, e.g., for shoe upper materials. The question arises, why animal-free materials (a), which are directly manufactured by preserving a grown structure combined with more or less intensive processing, show only poor mechanical resistance compared to leather.

The resulting structures of grown natural materials are intended to be an alternative for the fibrous structure of animal skin [ 11, 24, 25]. A typical representative is the fungus-based material Muskin ® taken from Phellinus ellipsoideus. The microscopic pictures show that the mycelium is composed of hyphae that represent the structure-forming component. Our measurements showed mainly polysaccharides as chemical structures. Therefore, it can be assumed that chitin forms the hyphae. The FTIR spectrum exactly fits that of other investigations [ 26]. The latter interpreted the spectra in more detail and also assigned proteins, lipids, and nucleic acids. However, the mechanical stability of the mycelium is limited. This may be caused by the limited stability of the hyphae itself, and the processed mycelium as shown elsewhere [ 11, 27]. The pictures of the cross section show that the fibers are oriented perpendicular to the surface. This also leads to poor mechanical stability. Presumably, the mechanical performance could be improved if the fibers were aligned along the direction of the mechanical load.

In contrast, Kombucha is a traditional Japanese beverage, which is prepared by a symbiosis of bacteria and yeasts metabolizing sugars into organic acids, ethanol, and carbon dioxide. In parallel, bacteria (e.g., Acetobacter xylinum) are secreting high molecular weight polysaccharides, which lead to a gel-like consistency. The intensively growing microorganisms can be harvested and the secreted polymers are used as a biogenic structure-forming material after a drying step [ 10]. The mechanical stability of the Kombucha material sample was much higher than that of Muskin ® but missed the requirements for shoe upper materials as well. While Muskin ® shows a loose and open structure, which allows water vapor to diffuse through the material, Kombucha is very tight but it absorbs higher amounts of water. Both microorganism-based materials appear homogenous in their cross sections.

The raw material of leather, the animal skin is composed of collagen, a structure-forming protein. Leather is built from intertwined fibrils and fibers, which are additionally cross-linked by leather tanning. The fibrous structure of leather shows a gradient in its material density from the grain to the reverse side. The final layer on top is composed of very thin and tight collagen fibers. The grown skin tissue shows a very high mechanical stability (tensile strength, tear strength), which is by 100 to 1000 times higher than that of the microorganism-based materials [ 5, 10, 11, 25, 26, 28]. The strength of leather can be related to the stability of the collagen fibers themselves and to the weaving and crosslinks between the fibers.

From the biological point of view, hyphae of microorganisms and the animal skin fulfill very different tasks in the respective organisms. The performance of natural materials had been summarized in the past in Ashby plots. Figure 4 provides an impressive overview of a couple of different natural materials and their mechanical limits [ 29]. Natural flexible load transferring materials appear with a density of ~1 Mg/m ³ and range from 0.1 MPa to more than 1000 MPa (marked red). The tensile strength of parenchymatous plant tissues is low (marked blue). Collagen-based materials such as skin and tendon appear to be very stable (red ellipse). High stability is also observed in structures of plants, which have to transfer load (wood, cellulose fibers).

It can be deduced from these considerations that grown natural materials will only exhibit flexible and mechanical resilience when load transferring structures are used. The animal skin covers a broad set of aimed functions. It has to protect the body for a long time against mechanical impact, it is flexible to allow mobility, and often it has to regulate the temperature and water balance. Plant fibers have to absorb the weight of the plant against gravitation and in load direction.

In contrast, the tissue-like structures of microorganisms appear as parenchymatous materials, based on fiber networks, which primarily offer active cells a matrix for metabolism (bacteria, fungi) and transportation of nutrients (hyphae). Therefore, they appear at the bottom of Figure 4. To overcome these mechanical deficiencies, it was proposed to stabilize the fiber network of Muskin ® by crosslinking agents [ 25, 26], or to adjust the softness of Kombucha materials by the addition of plasticizing agents [ 10]. However, this contradicts the multiscale idea, the variation of the density and the orientation of the fibers along their load direction, which would presumably better help to overcome the observed limitations.

The second concept to achieve highly functional leather-like materials with a high content of bio-based components takes up the principle of artificial leather. These materials simulate the structure of leather as multilayer material. The functions can be separated between the textile support, which has to fulfill the mechanical function (tensile strength, tear strength), the middle layer, by which feel and softness are adjusted, and the topcoat, which takes over the final optical appearance. A grain structure similar to that of leather is mostly achieved by embossing. Therefore, to increase the biogenic part of the materials, it would be effective to replace the polyester support with natural fibers. As shown in Figure 4, the natural fibers may show excellent mechanical stabilities. However, only Vegea ® and Teak Leaf ® use a cellulose-based fabric as support. The renewable content in these multilayer materials could also be increased by replacing synthetic polymers in the coating layers. Desserto ® and Appleskin ® adopt this principle. A part of PUR is replaced by agricultural by-products, which are used as fillers. A detailed analysis of the origin of the natural component and its content in relation to the bulk of the material was not possible, however. Nevertheless, the bulk of the materials remains to consist of polyurethane. In the case of Teak Leaf ®, a natural-appearing surface is created by imparting the natural leaf, which is covered by synthetic waxes. However, because of the missing elastic foam layer as used in artificial leather and its replacement by the plant leaf, the flex resistance is hampered and appears not adequately adjusted from a functional point of view.

As a third strategy to replace leather with animal-free materials for which plant-based non-woven fabrics are used. The fossil-based polyester textile support is exchanged by natural fiber alternatives as cotton, linen, etc. Ideally, the fabric would be finished with a biobased polymer. Pinatex ®, for example, is manufactured from pineapple leaf fibers, which are laboriously processed before they are coated by a thin polymer film that can be either fossil-based or from renewable resources to improve usability. Pinatex ® promotes its polymer finish to be polylactide, which can be produced fully bio-based [ 13, 30, 31, 32]. However, our analysis showed at least a remarkable content of PUR/acrylate in the finish. The very thin surface coating does not completely cover the fibrous non-woven, which leads to a hard surface with a fibrous appearance that withstands the flex test, however. The material appears more similar to a textile non-woven and the low mechanical resistance can be correlated directly to the low binder content of the fibers of the non-woven support. SnapPap ® is based on cellulosic fibers as well, but in contrast to Pinatex ®, the matrix is bound with acrylic acid-based polymers. Both materials neither simulate a leather structure nor do they appear as a leather surface. Therefore, they should rather be estimated as coated or impregnated textile than as artificial leather or leather alternative.

Figure 5 shows impressively the performance of the different materials in comparison to the references. Alternative materials have specific advantages, but none of the materials combines high mechanical strength and flex resistance with high water vapor permeability as in the case of leather.

4.2. Surfaces and Appearance

The surfaces of the materials are their "face." This is impressively shown with the applied leaf in Teak Leaf ® as an eye-catcher. The resulting structures appear optically interesting but do not fulfill the same function as the foam layer in engineered coated textiles. Other plant materials, which are used in similar constructions to achieve interesting optical properties are, e.g., cork based. They have not been investigated in this study but have to be supported as well by textiles to achieve suitable physical properties [ 33, 34, 35]. Therefore, the Teak Leaf ® solution appears more design-driven than it takes functional aspects into account.

To achieve sufficient functional properties of the surface of flexible materials often a final topcoat is applied, which then determines the optic and partially haptic and other useful properties of the materials, e.g., flex resistance, abrasion behavior, and soiling behavior. The water vapor permeability also depends on the tightness of the topcoat or of watertight layers in between. The thicker this layer the less the material allows vapor and gas permeation [ 36].

Leather as investigated usually shows only a very thin top coat to improve the soiling behavior. The flex resistance is very high. The water vapor permeability is in an appropriate range. Muskin ® and SnapPap ® show very open structures, which allow water vapor perfectly to diffuse. However, their performance characteristics, particularly the poor flex resistance, limits the long-time use. All other investigated materials are very tight against water vapor permeation. Used as a shoe material, this would lead to sweating of the feet and would reduce the comfort [ 37, 38] but the materials would be tight against rain if used as, e.g., bag or rain jacket.

The microscopic surface of SnapPap ® and Pinatex ® shows the fibrous non-woven fabric, which takes over the mechanical properties of the material. SnapPap ® and Pinatex ® do not appear leather-like. They show hard surfaces and an exposed fibrous non-woven structure. Applying a thicker polymer coating and embossing a grain structure would presumably lead to a leather-like optic. In this case, considerations regarding water vapor permeability for coated textiles have to be taken into account.

5. Conclusions

None of the alternative materials achieved the properties of leather according to the applied reference values, although many of them are offered as a leather alternative ( Figure 5). The question of why it is difficult to achieve these properties by alternative natural materials is answered with the different biological functions of the used materials. Leather is a multi-scale material, which is designed by nature to fulfill load transferring and metabolic functions. It shows a gradient in the tightness of the structure composed of differently fine hydrophilic protein fibers. Each part of the structure takes over a specific function. The reticular layer, which consists of coarse fiber bundles is responsible for the high mechanical resistance (tensile and tear strength). The destruction of the fiber network of the grown tissue leads to a decrease of the mechanical stability by 10 times [ 28]. This can only slightly be improved when the fibers are again bound by binding agents (e.g., middle layer leather board of Noani ®). The more compact and finer fibers of the papillary layer of leather and the grain membrane cause the leather-like appearance and the tight structure on top. Nevertheless, the water vapor permeability is high if no tight synthetic topcoat is applied. The hydrophilic fibers of leather can absorb much water, which leads to high comfort if compared with the synthetic alternatives. The biogenic non-woven textiles Pinatex ®, SnapPap ®, and Kombucha show similar water absorption values as leather but lack mechanical and flexural strength. Therefore, it remains a challenge and an aim to reproduce the function of the bionic structure of the skin with alternative biological techniques as has already been mentioned many years ago [ 29]. When agricultural by-products are added to polymer layers of artificial leathers, the biobased content of the materials is raised but no physical advantage over the reference material can be measured. Only a proper life cycle analysis would allow assessing the associated advantage.

Supplementary Materials

The following are available online at https://www.mdpi.com/2079-6412/11/2/226/s1, Figure S1: Sample shoe upper leather; (a) cross section, (b) surface, Figure S2: Sample Muskin ®; (a) cross section (25 times magnification), (b) surface, Figure S3: Sample Kombucha; (a) cross section (100 times magnification), (b) surface, Figure S4: Sample PUR-coated textile; (a) cross section, A: thin compact top layer, B: foamed layer, C: textile carrier, (b) surface, Figure S5: Sample Desserto ®; (a) cross section, A: compact top layer, B: foamed layer, C: textile carrier, (b) surface, Figure S6: Sample AppleSkin ®; (a) cross section, A: compact top layers, B: foamed layer, C: impregnated layer with a textile carrier, (b) surface, Figure S7: Sample Vegea ®; (a) cross section, A: compact top layer, B: foamed layer, C: textile carrier (b) surface, Figure S8: Sample Teak leaf ®; (a) cross section, A: leaf with a transparent top layer, B: textile layer 1, C: textile layer 2, (b) surface, Figure S9: Sample Pinatex ®; (a) cross section, non-woven with a compact top layer, (b) surface, Figure S10: Sample SnapPap ®; (a) cross section, (b) surface, Figure S11: Sample Noani ®; (a) cross section (25 times magnification), A: microfiber layer, B: leather board layer, C: textile carrier, D: foamed layer, E: compact layer, (b) surface, embossed region, Figure S12: FTIR spectrum of Desserto ® as an example of a PUR-coated material with typical molecular vibrations (3359 NH; 3931 CH ₂; 2862 CH ₂; 1744 C=O; 1635 O=C-NH; 1554 Amid; 1464 CH ₂; 1257 C-O-C).

Author Contributions

Conceptualization, S.D., H.S., and M.M.; methodology, H.S. and S.D.; validation, S.D. and H.S.; investigation, S.D. and H.S.; data curation, S.D., A.M., H.S. and M.M.; writing-original draft preparation, A.M. and M.M.; writing-review and editing, H.S., A.M. and M.M. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Informed Consent Statement

Data Availability Statement

Acknowledgments

We thank the German Leather Association (VDL) for the donation of all samples.

Conflicts of Interest

The authors declare no conflict of interest.

References

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Figure 1. The principal structure of leather ( A) and artificial leather ( B). Leather still reflects the histological structure of skin with grain membrane ( a), papillary layer ( b), reticular layer ( c), and hair channels ( d). Artificial leather is composed of a topcoat ( e), a compact layer ( f), a foamed middle layer ( g), and the textile support ( h) (drawings by Enno Kluever, FILK).

Figure 2. Leather ( A) and a material with a naturally grown fiber structure (Muskin ®) ( B); structure of a typical coated textile (example Desserto ® ( C); ( a) topcoat; ( b) foamed middle layer; ( c) textile support); non-woven made of natural fibers (example Pinatex ®) ( D). The scales between Muskin ® and the other samples differ by 2.5 times.

Figure 3. Surfaces of the investigated materials: Naturally grown material (Leather ( A), Muskin ® ( B), Kombucha ( C), Teak Leaf ® ( D)); embossed surfaces of coated textiles (PUR-coated textile ( E), Desserto ® ( F), Appleskin ® ( G), Vegea ® ( H)); fiber structures of non-woven natural fibers (Pinatex ® ( I), SnapPap ® ( K)), and micro-fiber material (Noani ® ( L), embossed).

Figure 4. "A material property chart for natural materials, plotting strength against density. (...) Structurally efficient materials are light and strong." Reprint with permission from [ 29] Copyright 2021 Taylor& Francis. Natural flexible load transferring materials appear with a density of ~1 Mg/m ³ and range from 1 MPa to more than 1000 MPa (marked red). The tensile strength of parenchymatous plant tissues is low (marked blue).

Figure 5. Comparison of the physical properties of the materials. The values are normalized to the maximum value measured in this survey for the respective parameter.

Table 1. Samples and their composition.

Name

Color

Composition (from Top to Backside)

Shoe-upper leather

brown

Full-grain bovine leather; typical leather structure; finished with a very thin topcoat

Kombucha

brown

Dense compact material based on polysaccharides, contains talcum, some heterogeneous inclusions of unclear origin

PUR coated textile

grey

Coated textile with thin compact topcoat (PUR), a layer underneath (PUR) filled with heterogeneous particles made of modified cellulose and a textile carrier based on polyester, material made by coagulation process

Table 2. Physical properties.

Physical Properties

Thickness

Tensile Strength

Tear Res.

WVP

WVA

Flex Res.

ISO 17186-A

ISO 3376

ISO 3377-1

ISO 14268

ISO 17229

ISO 32100

(mm)

(N/mm²)

(N/mm)

(mg/(cm² × h))

mg/cm²

Flex Cycles to Grade ≥ 2

Naturally grown material

Leather

1.93

39.5

82.9

4.6

8.4

>200,000

Kombucha

0.29

9.7

5.1

0.1

9.2

10,000

Coated textile

PUR coat text.

1.37

10.2

17

1.1

1.4

200,000

Non-wovens of plant fibers

Pinatex ®

1.43

4.5

31

2.5

3.8

150,000

AMA Style

Meyer M, Dietrich S, Schulz H, Mondschein A. Comparison of the Technical Performance of Leather, Artificial Leather, and Trendy Alternatives. Coatings. 2021; 11(2):226. https://doi.org/10.3390/coatings11020226

Chicago/Turabian Style

Meyer, Michael, Sascha Dietrich, Haiko Schulz, and Anke Mondschein. 2021. "Comparison of the Technical Performance of Leather, Artificial Leather, and Trendy Alternatives" Coatings 11, no. 2: 226. https://doi.org/10.3390/coatings11020226

# data[].attributes.attachment_link.title
Comparison of the Technical Performance of Leather, Artificial Leather, and Trendy Alternatives

# data[].attributes.attachment_link.description
The market for biogenic and synthetic alternatives to leather is increasing aiming to replace animal-based materials with vegan alternatives. In parallel, bio-based raw materials should be used instead of fossil-based synthetic raw materials. In this study, a shoe upper leather and an artificial leather, and nine alternative materials (Desserto®, Kombucha, Pinatex®, Noani®, Appleskin®, Vegea®, SnapPap®, Teak Leaf®, and Muskin®) were investigated.

# data[].attributes.headline
A journal article from Sustainability entitled "Exploring the Sustainability Concepts Regarding Leather Apparel in China and South Korea."

# data[].attributes.subject
A journal article from Sustainability entitled "Exploring the Sustainability Concepts Regarding Leather Apparel in China and South Korea."

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by 1 and 2,*

Da Vinci College of General Education, Chung-Ang University, Seoul 06974, Korea

Department of Fashion Design, Chung-Ang University, Anseong, 17546, Korea

Author to whom correspondence should be addressed.

1. Introduction

The products and services incorporating sustainable and pro-environmental attributes and considerations have become increasingly appealing to consumers [ 1, 2, 3]. Public concerns about the quality of life of human beings as well as the quality of natural environments and ecosystems have led to the increasing importance of sustainability for governments and for all industries, including the apparel industry in both China [ 4] and Korea [ 5].

Severe air pollution problems, such as the high level of particulate emissions and climate change caused by global warming, have become serious social problems, environmental concerns, and sustainability issues in both China and South Korea [ 6]. Since sustainable consumption behavior has been comparatively neglected by Asian consumers compared with Western consumers [ 7], examining the similarities or differences between Chinese and Korean segments is of interest to comprehend sustainable Asian behaviors. The global market for eco-friendly apparel is relatively small (1% of the total world-wide apparel market). However, this market is predicted to double over the next 10 years owing to increased media attention, growing consumer awareness of environmental and sustainability issues specific to apparel and textile production, and greater commitment among apparel firms to execute sustainable and socially responsible approaches to manufacturing [ 8].

Recently, a new generation of designers has been building brands with more conscious and sustainable approaches to fashion at their core. Whether they source fabrics through collectives empowering female workers (Richard Malone), use only recycled cottons and plastics (Alyx), or transform vintage scarves into resolutely contemporary dresses (Marine Serre), their approaches are aimed at sustainability [ 9]. Similarly, long-established apparel brands, including Levi Strauss, American Apparel, and Burton, have responded to growing media attention and consumer interest by altering their product design, development, and sourcing strategies to achieve sustainable performance [ 10]. However, leather is not easily amenable to the ideals of sustainable consumption, as its production is responsible for the problems of animal cruelty and environmental destruction related to the pollution caused by the toxins used in the tanning process. Given the increased interest on the part of consumers in the claims of sustainability by makers of apparel products [ 11, 12, 13, 14], this study focused on the research and development of eco-friendly faux leather apparel (E-FLA), which is eco-friendly and bio-degradable, protecting both animals and the natural environment. As part of laying the groundwork for introducing and promoting E-FLA to potential sustainability-oriented consumers, this study aims to identify the socio-psychographic factors of consumers which drive their behaviors in purchasing and using E-FLA through the application of the theory of planned behavior.

The theory of planned behavior (TPB) model is widely applied to analyze consumers' behaviors [ 15, 16]. The TPB appears to be a robust way of explaining pro-environmental and pro-social behaviors [ 17]. Sustainable consumption can create an individual, symbolic feeling of advantage which is associated with a certain lifestyle (activities, interest, and opinions) or an expression of personal identity and other social values or beliefs. Within the framework of the TPB, this study identifies the influential determinants (environmental knowledge, perceived consumer effectiveness, sustainable consumption beliefs, and self-enhancement) of behavioral intention to buy, use, and recommend E-FLA.

Despite the rising concerns for sustainability issues in society, research has tended to neglect the multi-dimensional sustainable consumption beliefs regarding the apparel and textile industry. Additionally, studies in the context of textiles and apparel focused on the process of the formation of beliefs about sustainable consumption, including antecedents and outcome factors within Asian consumer sectors, have been limited. A main assumption among researchers has been that any increase in environmental knowledge [ 18, 19] and perceived consumer effectiveness, defined as the notion that the efforts of an individual can make a difference in solving problems [ 20], will increase environmental concern and beliefs. Abdul-Muhmin [ 21] indicated that consumers' self-enhancement-the positive emotions of achievement that a consumer expects to derive from consuming in a pro-environmental manner-could affect their pro-environmental behavioral intentions. Hence, this study assumes that consumers who have a strong sustainable consumption belief stemming from a high level of environmental knowledge and perceived consumer effectiveness may have a stronger purchase intention with regard to E-FLA products, mediated by a high self-enhancement feeling related to sustainable consumption.

The environment and animal-friendly faux leather is a newly-developed product in South Korea with superior performance and bio-degradability. In order to encourage the use of this sustainable product in the Chinese and South Korean marketplaces, this study examines behavioral intention to buy, use, and recommend E-FLA and investigates the pro-environmental ideas and sustainable consumption beliefs of potential consumers. Although many studies applying the TPB model have predicted sustainability behavior intentions [ 3, 22, 23], the potential use of the TPB model related to sustainable consumption on the part of Asian consumers in the fashion industry context has been neglected [ 24]. Thus, this study applies the TPB model to Chinese and South Korean consumers in relation to the apparel and textile industry. Recently, researchers [ 6, 25] have suggested that it is helpful to include other consumer psychographic constructs into the TPB model when investigating consumers' sustainability intentions. Hence, this study aims to modify and use the TPB model to investigate how the relationships among a variety of consumer characteristics (i.e., environmental knowledge, perceived consumer effectiveness, multi-dimensional sustainable consumption beliefs, and self-enhancement); the behavioral intention to buy, use, and recommend E-FLA; and culture, can indicate novel prospects for achieving insights related to developing theories and marketing strategies for sustainable consumption.

2. Background

2.1. Sustainability in the Apparel and Textile Industry: Eco-Friendly Faux Leather Apparel (E-FLA) Products

Following the 1983 World Commission on Environment and Development (WCED), chaired by Gro Harlem Brundtland, a 1987 report named "Our Common Future" was published, defining Sustainable Development as the "development that meets the needs of the present without compromising the ability of future generations to meet their own needs''.

The Brundtland report highlighted three fundamental components to sustainable development: environmental protection, economic growth, and social equity. The concept of sustainability was focused on finding strategies to promote economic and social advancement in ways that avoid environmental degradation, over-exploitation, or pollution, while less productive debates about whether to prioritize development or the environment were sidelined [ 26].

The apparel and textile industry must take its philosophy of sustainability seriously and face its responsibility to society, in particular, because the industrial production process has been associated with the exploitation of both natural resources and people. An issue is the general growth in awareness of consumers over the past three decades of the impact their consumption on human beings and nature. The concept of sustainability in fashion is a vital part of the approach currently being taken by parts of the apparel and textile industry for whom environmental consciousness is a part of marketing [ 27, 28]. In particular, a growing number of sustainable clothing companies, such as American Apparel, Edun, and Gossypium, are striving to attract young consumers by producing fashionable clothes [ 29, 30]. The principle motivating them is that of sourcing garments environmentally while providing good working standards and conditions for workers and ensuring a sustainable business model in the clothes' country of origin.

The International Cooperation (1999) established a research project called "Leather Production of the Future" to reduce the negative environmental impacts of leather production with a global perspective. In addition, the United Nations Industrial Development Organization (2003) developed a methodological series of steps to help leather producers worldwide minimize the ecological impact of leather production. These methods include the treatment of waste, the efficient use of chemicals, the use of new bio-degradable chemicals for tanning, and having up-to-date equipment that can reduce effluent production and solid waste discharge. Due to the cruelty to animals involved in the production of natural leather and the pollution caused by the production of faux plastic leather, alternatives such as bio-degradable leather need to be researched and developed to protect the eco-system. However, apparel companies may struggle to sell pro-environmental and sustainable faux leather fashion items because of consumers' hesitancy when faced with newly developed sustainable options. Therefore, this study explores the behavioral intention to buy or use newly-developed E-FLA products as an important prerequisite to introducing them to real markets.

2.2. Theoretical Frameworks: Theory of Planned Behavior

Further, departing from his original stance, Ajzen (1991) [ 16] stated that "the theory of planned behavior is, in principle, open to the inclusion of additional predictors if it can be shown that they capture a significant proportion of the variance in intention or behavior after the theory's current variables have been taken into account" (p. 199). More modifications to the theory have proposed the addition of pro-environmental obligations (e.g., [ 42, 43, 44]). The majority of research on sustainable consumption has focused on Western consumers. The drawbacks of previous research range from the unidimensional study of sustainable consumption beliefs and the limitation of the products studied to a few categories (primarily food). Thus, this study aims to demonstrate the multi-dimensionality of sustainable consumption beliefs as a factor affecting sustainable behavioral intentions related to apparel products among Asian consumers (specifically, in China and South Korea).

2.3. Proposed Modifications to the TPB

Although the TPB may be the most widely supported model, various additional modifications have been proposed. This study proposes further theoretical development of the TPB model within the context of sustainable apparel consumption.

Environmental Knowledge (EK): Knowledge is regarded as vital for successful action. Consistent with this idea, knowledge-based promotion and campaigns have continually been a popular means of encouraging certain behaviors, such as pro-environmental behaviors, among members of the public [ 45]. Knowledge is considered a means to overcome psychological barriers such as ignorance and misinformation. It is viewed as a necessary, though generally inadequate, precondition for successful action. In other words, although knowledge does not always have the intended effect on a target behavior itself, it may at least promote other mechanisms that facilitate behavior change [ 46]. Arcury and Johnson [ 18] described environmental knowledge as information that individuals have about the environment, the ecology of the planet, and the influences of human actions on the environment. A main assumption among researchers has been that an increase in knowledge will increase environmental concerns. Several studies have indicated that knowledge of environmental problems is related to environmental concern [ 47, 48] and behaviors, such as preserving the Earth's resources [ 49].

Perceived Consumer Effectiveness (PCE): Perceived consumer effectiveness is defined as a domain-specific belief that the efforts of an individual can make a difference in the solution to a problem [ 20]. PCE is related to the concept of perceived behavioral control, which has been studied by theorists in the areas of helplessness, the locus of control and perceived control [ 50]. The common thread in these areas is that the subjects' actions and/or intentions are affected by the degree to which they believe the occurrence of an event can be affected by their actions [ 51]. According to Kim and Choi [ 52], people can develop a sense of ineffectiveness through witnessing failure by others and through their own experiences of failure or being out of control. The degree to which a person feels that he or she has little control over the performance of a behavior has been shown to significantly reduce behavioral intentions and behaviors, even under circumstances where attitudes and/or social norms toward the action are very favorable [ 39, 53]. Similarly, PCE is expected to affect intentions and behavior if individuals believe that their behavior will or will not lead to the desired result.

Self-Enhancement in Sustainable Consumption (SE): Self-enhancement is defined as the positive emotion of achievement or satisfaction that a consumer expects to come from consuming products sustainably. According to Abdul-Muhmin [ 21], consumers may experience satisfaction from being able to contribute toward environmental conservation. This is among the perceived psychological consequences of pro-environmental behavior. Abdul-Muhmin [ 21] have indicated that this cognitive satisfaction experienced by consumers could affect pro-environmental behavioral intentions. Related to this concept, self-actualization motivations are those in which an individual seeks self-fulfillment and an enriching experience from sustainable consumption [ 59, 60]. Drawing on Maslow's conception of a self-actualized individual, people with self-actualization motives are driven by the desire for growth, rather than (perceived) deficiency. They seek the experience for egoless, selfless, detached reasons, so this fulfillment of needs has underlying altruistic motivations. A defining characteristic of this category of motivation is that individuals seek to help others rather than themselves, so improved welfare for others is a key outcome. Consumers who are concerned with sustainability may express altruism by, for instance, buying fair trade products to help poor people to have better lives. They may also prioritize products from companies that practice corporate social responsibility. In this way, they contribute to supporting companies that respect human and animal welfare and that are environmentally friendly.

Behavioral Intention (BI) to buy, use, and recommend E-FLA products: This notion is conceptualized as a consumer's readiness to act, or a positive predisposition to act, in a sustainable way. Environmental concern and perceived psychological consequences are the key hypothesized determinants of this concept. The expected positive effect of concern is based on empirical results that show that environmental concern positively influences the consumers' willingness to pay a premium for environmentally friendly product alternatives [ 21]. The indirect evidence from the theory of reasoned action (TRA) supports the hypothesized effect of perceived psychological consequences on willingness. If, as suggested by the TRA, salient consequences of behavior affect behavioral intentions, then the perceived psychological consequences of behavior should affect behavioral willingness. In other words, all things being equal, consumers who anticipate positive emotions of achievement or satisfaction derived from their own efforts toward protecting the environment should show more willingness to engage in sustainable actions than those who do not anticipate deriving such emotions.

Conceptual Framework and Hypotheses: Based on the theoretical and practical evidence reviewed in the preceding paragraphs, the hypotheses investigated in this study are summarized below:

Hypothesis 1 (H1).

Environmental knowledge has a positive effect on sustainable consumption beliefs (H1a, pro-environmentalism; H1b, social responsibility, H1c, animal conservation).

Hypothesis 2 (H2).

Perceived consumer effectiveness has a positive effect on sustainable consumption beliefs (H2a, pro-environmentalism; H2b, social responsibility, H2c, animal conservation).

Hypothesis 3 (H3).

Sustainable consumption beliefs (H3a, pro-environmentalism; H3b, social responsibility, H3c, animal conservation) have positive effects on the self-enhancement resulting from sustainable consumption.

Hypothesis 4 (H4).

The self-enhancement resulting from sustainable consumption has a positive effect on behavioral intentions to buy, use, and recommend E-FLA products.

Based on the review of the literature and hypotheses developed above, the authors created a conceptual framework to investigate the relationship among environmental knowledge (EK), perceived consumer effectiveness (PCE), sustainable consumption beliefs (SCB), self-enhancement resulting from sustainable consumption (SE), and behavioral intentions to buy, use, and recommend E-FLA products (BI), as shown in Figure 1.

3. Methodology

3.1. Instrument Development

3.2. Sample and Data Collection

A total of 450 respondents completed the survey, and the data were gathered from online respondents from China (N = 225) and Korea (N = 225) with participants aged between 20 and 40 years. The female sample was collected purposefully from the residences of the metropolitan areas of Shanghai and Beijing in China and Seoul in South Korea, and the participants were recruited through a qualified online survey firm. The sample is described as follows: 72.4% of the Chinese respondents indicated they were married and 53.8% of the Korean respondents indicated they were married; 54.7% of the Chinese had children and 47.6% of the Koreans had children; most of the respondents in both the Chinese (93.8%) and Korean (66.6%) groups had received undergraduate education; and the majority of the Chinese (87.5%) and Koreans (76%) perceived themselves as having a middle social status.

The general level of awareness of E-FLA products was examined: only 12.4% of the Chinese respondents and 5.8% of the Koreans were aware of them; 64.9% of the Chinese respondents and 47.6% of the Korean respondents had heard about E-FLA products; 22.7% of the Chinese respondents and 46.7% of the Korean respondents had no idea about them. Only one-third of the Chinese respondents (31.5%) and 11.1% of the Korean respondents had purchased general E-FLA products, which indicates a low level of acceptability of E-FLA products in both countries. For the respondents who answered that they had purchased general E-FLA products, most (71.4% in China and 72% in Korea 72%) had bought a fashion item ( Table 1). Thus, general E-FLA products have entered the early adoption stage of product diffusion in both countries.

4. Results and Analysis

4.1. Internal Consistency, Item Analysis, and Exploratory Factor Analyses

To test the unidimensionality of the latent constructs, an exploratory factor analysis (EFA) was conducted [ 63]. The EFA on each construct showed a single underlying factor for each construct. In addition, the Cronbach's alpha scores, which ranged from 0.75 to 0.90, showed a satisfactory level of construct reliability [ 64].

4.2. Measurement Model

The latent variables were constructed and then tested in a measurement model employing a confirmatory factor analysis (CFA). The results of the measurement model demonstrated that the dimensionality of each construct was well identified. The model generated satisfactory fits, and all factor loadings were statistically significant. By means of the AMOS 18.0 statistical program, CFA was performed to estimate the measurement model, following Anderson and Gerbing's [ 65] two-step approach. The original measurement model analysis, including 34 items, indicated that the model fit was not satisfactory, and the model needed improvement. A series of scale purification processes [ 66] was used to remove 13 items, including three items for EK, three items for PCE, and seven items for SCB. The final measurement model generated an acceptable fit: χ ² = 344.16, df = 164, χ ²/df = 2.09, p < 0.001, CFI = 0.96, GFI = 0.93, AGFI = 0.91, NFI = 0.93, RMSEA = 0.04, RMR = 0.06, and all coefficients were significant.

The convergent validity of the constructs was supported by a significant t-value of each item's estimated path coefficient on its posited latent construct [ 67, 68]. All estimated path coefficients had t-values that were significant at the p < 0.05 level. The average variance extracted (AVE) of each construct exceeded the cutoff of 0.5, also supporting the convergent validity of each scale [ 69]. The CFA factor loadings (all above 0.6) were all in the acceptable range, suggesting the unidimensionality of each construct [ 68] ( Table 2). As this study expected, each unidimension of EK, PCE, SE, BI relating to E-FLA products, and three dimensions of SCB were identified. The discriminant validity was supported as the AVE between each pair of constructs was greater than Φ² (i.e., the squared correlation between two constructs) (see Table 3).

The measurement invariance between the Chinese and the Korean groups was tested by multi-group CFA ( Table 4). An examination of the chi-square differences between a constrained versus an unconstrained model revealed that the conditions of metric (i.e., measurement weight) and scalar (i.e., structural covariance) invariance were satisfied in all latent variables of the proposed model. Thus, the two groups of the sample demonstrated measurement invariance, which means the proposed model can test the hypothesized relationships, and the moderating role of country (China and South Korea) can also be tested [ 70].

4.3. Hypothesis Testing: Validating Sustainable Consumption with the TPB Model

Structural equation modeling (SEM) analysis was used to examine the hypothesized relationships. The structural model identified two variables (EK and PCE) as exogenous latent constructs, and the other variables (PE, SR, AC, SE, and BI) were given as endogenous constructs. The hypothesized structural model showed a suitable fit (χ ²(df) = 393.72(167), CFI = 0.96, GFI = 0.92, AGFI = 0.91, NFI = 0.92, RMSEA = 0.05, RMR = 0.07).

H1 was concerned with whether EK has positive influences on the three dimensions of SCB (PE, H1a; SR, H1b; AC, H1c). EK was shown to strongly affect all SCB dimensions in this study: PE (β = 0.30, p < 0.001), SR (β = 0.43, p < 0.001), and AC (β = 0.39, p < 0.001). Thus, H1 was supported, indicating the significance of EK in formulating SCB. Environmental knowledge is a necessary antecedent factor of an individual's pro-social consciousness and behavior (Frick et al., 2004). H2 was concerned with whether PCE has positive effects on the three dimensions of SCB (PE, H2a; SR, H2b; AC, H2c). PCE was shown to robustly affect all SCB dimensions in this study: PE (β = 0.59, p < 0.001), SR (β = 0.41, p < 0.001), and AC (β = 0.38, p < 0.001). Thus, H2 was supported, indicating the significance of PCE in creating SCB. Consumers have sustainability concerns and beliefs when they think their efforts can have effects on the whole society [ 20].

H3 was concerned with whether the dimensions of SCB (PE, H3a; SR, H3b; AC, H3c) positively affect SE. The results showed that, among the three SCB dimensions, PE (β = 0.53, p < 0.001) and SR (β = 0.34, p < 0.001) had positive significant effects on SE, while AC (β = 0.04, p > 0.05) had no effect on SE. Therefore, H3a and H3b were supported and H3c was rejected. H4 was related to the positive effect of SE on BI to buy, use, and recommend E-FLA products. SE was shown to significantly affect BI to buy, use, and recommend E-FLA products (β = 0.69, p < 0.001). Hence, H4 was supported. In generating consumer intention to use, buy, or recommend E-FLA products to others, SE was the determinant in the sustainable consumption for Chinese and Korean consumers. In sum, nine of the hypotheses proposed in the present study were supported, which suggests that the TPB model is compatible with Asian sustainable consumption behavior. Based on the results, the TPB was able to detail the determinants of an individual's decision to carry out sustainable behaviors related to apparel purchase, consistent with previous research focusing on other areas.

4.4. Country Differences between China and South Korea

To investigate the moderating effect of respondents' nationality between China and South Korea, multi-group structural equation modeling (MGSEM) was conducted. The identification of the measurement invariance between the two respondent groups was necessary before MGSEM could be carried out. The unconstrained model assumed that the invariance had the same factors and path pattern in the two country estimations. The fit of the unconstrained model was shown to be satisfactory (χ ²(df) = 602.24(326), CFI = 0.95, GFI = 0.90, NFI = 0.90, RMSEA = 0.04, RMR = 0.08), with a statistically significant t-value for factor loadings exceeding 0.60. The full invariance model was tested by constraining the metric of the factor loading (measurement weight) to be invariant across the two countries. There were no significant differences in the chi-square value (Δχ ²(Δ df) = 7.16₍₁₄₎, p > 0.05) between the unconstrained model and the measurement weight-constrained model (χ ²(df) = 609.39(340), CFI = 0.95, GFI = 0.89, NFI = 0.89, RMSEA = 0.04, RMR = 0.08). Therefore, metric invariance was supported, and the two countries' structural models were found to be invariant.

Upon validation of the measurement invariance between the Chinese and Korean groups, MGSEM was carried out to compare the hypothesized relationships between the two consumer groups. The Chinese consumers' sustainable consumption was motivated by pro-social values and multi-dimensional sustainable consumption beliefs and self-enhancement along three paths: from EK through PE and then through SE to BI to buy, use, and recommend E-FLA products; from EK through SR and then through SE to BI to buy, use, and recommend E-FLA products; and from PCE through PE and then through SE to BI to buy, use, and recommend E-FLA products (see Figure 2 and Table 5).

The Chinese group showed sustainable consumption beliefs including PE and SR arising from EK and PE stemming from PCE. PE and SR were found to be important determinants in generating the emotional feeling of enhancement or satisfaction with sustainable consumption. The AC of consumers' sustainable consumption beliefs may not be a positive determinant for raising SE in China. The mediation effects of PE and SE were shown to lead to BI to buy, use, and recommend E-FLA products.

The South Korean group's sustainable consumption intentions related to E-FLA products occurred along four paths, showing both similarities and differences between the Chinese and South Korean samples: from EK through PE and then through SE to BI; from EK through SR and then through SE to BI; from PCE through PE and then through SE to BI; and from PCE through SR and then through SE to BI (see Figure 3 and Table 5).

The mediation roles of PE and SR and SE were shown to lead to positive BI to buy, use, and recommend E-FLA products. The Korean group demonstrated sustainable consumption beliefs including PE and SR arising from both EK and PCE. PE and SR were found to be significant factors in generating the emotional feeling of enhancement or satisfaction with sustainable consumption. The AC of consumers' sustainable consumption beliefs may not be a positive determinant for increasing SE in South Korea, similar to the results for China. The mediation effects of PE, SR, and SE were shown to lead to BI to buy, use, and recommend E-FLA products in the South Korean group.

5. Discussion and Conclusions

Following on from the evolution of bio-based polyurethane and nanocellulose techniques, eco-friendly leather apparel (E-FLA) has been newly developed as a pro-environmental and animal-protective leather alternative for the Chinese and Korean apparel and textile marketplaces. This study examined the sustainable consumption behavior intentions to buy, use, and recommend E-FLA products following the theory of planned behavior approach, in which eco-friendly consumers attain environmental knowledge and perceive consumer effectiveness, form sustainable consumption beliefs, and use these beliefs to determine their willingness to buy, use, and recommend E-FLA products. Indeed, the TPB approach to understanding sustainable consumption behavior has been theoretically validated within a cultural-individual perspective. The cultural discrepancies and similarities are noteworthy when sustainable consumption beliefs indicate different directions for sustainable consumption decision-making.

First, the dimensionality of the modified TPB framework was demonstrated in the three dimensions of sustainable consumption beliefs and the unidimensions of environmental knowledge of apparel, perceived consumer effectiveness, self-enhancement of sustainable consumption behavior, and behavioral intention to buy, use, and recommend E-FLA products. The results indicated that environmental knowledge of apparel and perceived consumer effectiveness motivate positive perceptions of pro-environmentalism and social responsibility and result in a willingness to buy, use, and recommend E-FLA products. In particular, when pro-environmental and socially responsible consumers have emotional feelings of achievement from consuming pro-environmentally, they are likely to have positive behavioral intentions to buy, use, and recommend E-FLA products.

Second, the results support most of the hypotheses. Environmental knowledge and perceived consumer effectiveness were shown to lead to positive sustainable consumption beliefs, but no significant impact of a conspicuous value was found. However, a conspicuous value was found to lead to a desire for pro-environmental or pro-social behaviors, particularly, if eco-friendly products were expensive [ 71]. The nature of the E-FLA products might involve connotations of being cheaper or of lower quality than natural leather products. From another point of view, in the sustainable consumption context, consumers form their beliefs based on intrinsic perspectives rather than on the social context. Vitell et al. [ 72] found that consumers are guided more by values than by consequences when making sustainability-oriented decisions. Values are considered to be the one of the most abstract forms of individual knowledge. Therefore, tying a specific product, service, or idea to a value increases the ease with which the specific item can be stored and remembered [ 73]. Self-enhancement in sustainable consumption behavior positively mediates sustainable beliefs and behavioral intentions. A feeling of satisfaction is an efficient motivation for creating sustainable consumption behavioral intentions to buy, use, and recommend E-FLA products.

Third, this study reveals the cultural disparities in relation to the TPB framework between China and Korea, suggesting the need for further research in marketing E-FLA to these two countries. A conclusion consistent with the findings related to both countries assessed in this study is that the TPB framework is a relevant theoretical and practical model for both countries for understanding and predicting the marketability of E-FLA products. The discrepancy is founded on the emphasis in each country with regard to the TPB construct: Chinese consumers actively use their EK to advance their positive behavioral intentions, while Korean consumers employ both EK and PCE to avoid uncertainty in their decision-making processes.

6. Limitations and Future Research

Given the lack of current literature related to sustainable consumption practices in the clothing and textiles area, the results presented here provide a theoretical foundation for a systemic approach for analyzing people's consumption processes by applying the TPB model. However, due to the exploratory nature of this study, a number of drawbacks limit the generalization of its findings. First, the use of purposive sampling limits the generalization of the research, as this study restricted the sample frame to specific residence areas and age samples. Therefore, the sample may not be representative of the whole population of sustainable product users. In addition, due to growing interest in North Korea worldwide, a sample from North Korea, whose database has been very limited previously, will hopefully be collected in future research. Second, there might be some differences in sustainable consumption behaviors based on demographic factors including age, gender, occupation, and marital status. Further research needs to explore interactions between sustainable consumption and other demographic factors or consumer characteristics (i.e., sustainable consumption experience) or marketing perspectives (i.e., information about faux leather products such as eco-labels). Third, although this study applied the TPB model for understanding consumers and their connected perceptions, other business considerations such as fair-trade resources, pricing components, implementation, capabilities, and sustainability could be examined to measure business performance. Lastly, cultural and case-specific discrepancies must be considered before the study results are extended to other cultural and industry contexts.

Beyond these limitations, there are various implications for future research. Given the growing interest in sustainable consumption from societies, industries, and consumers, comprehending these dynamics can allow policy enforcers, marketers, and researchers to devise appropriate ideas and practical applications of E-FLA product stewardship and to present them to academia and industries. This cross-cultural study focusing on sustainable consumption behavior demonstrates the current understanding, evaluation, and potential appropriation of alternative consumption practices.

Author Contributions

H.J.J.: Article writing, research model establishment and questionnaire development; K.W.O.: Article writing, project administration, conceptualization and fund acquisition.

Funding

This research was supported by the Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Science, ICT & Future Planning (Grant No. NRF-2017R1A2B4005315).

Conflicts of Interest

The authors declare no conflicts of interest.

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Variable

Chinese

Korean

Total

Frequency

Percent

Frequency

Percent

Frequency

Percent

Previous purchase items of E-FLA products a

Less than 10% b

117

52.0

104

46.2

221

49.4

Factors and Items

EFA

CFA

Factor Loading

Factor Loading

t-Value

CR

AVE

0.85

0.82

- a

Model Fit Measures

Model Differences

χ²

Df

p

RMSEA

CFI

Δχ²(Δdf)

Hypothesized Relationships

Chinese

Korean

β

SE

CR

β

SE

CR

AMA Style

Chicago/Turabian Style

# data[].attributes.attachment_link.title
Exploring the Sustainability Concepts Regarding Leather Apparel in China and South Korea

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Sustainability in business and personal life has increased over the past few years and is continuing to develop. Consumption in the clothing and textiles industry causes a significant impact on the environment and utilizes unsustainable practices, from clothing production to use and disposal.

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A journal article from API Conference Proceedings entitled "Vegan leather: An eco-friendly material for sustainable fashion towards environmental awareness."

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A journal article from API Conference Proceedings entitled "Vegan leather: An eco-friendly material for sustainable fashion towards environmental awareness."

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Vegan leather: An eco-friendly material for sustainable fashion towards environmental awareness

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The earth getting warmer, habitat is destroyed, synthetic dyes impact on the environment and human health, animal skin and hair are used to create expensive fas

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A Ted Talk by Suzanne Lee entitled "Grow Your Own Clothes"

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A Ted Talk by Suzanne Lee entitled "Grow Your Own Clothes"

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Designer Suzanne Lee shares her experiments in growing a kombucha-based material that can be used like fabric or vegetable leather to make clothing. The process is fascinating, the results are beautiful (though there's still one minor drawback ...) and the potential is simply stunning.

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A Ted Talk by Dan Widmaier entitled "The Future of Fashion"

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A Ted Talk by Dan Widmaier entitled "The Future of Fashion"

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The Future of Fashion – Made from Mushrooms | Dan Widmaier | TED

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A Ted Talk by Andras Forgacs entitled "Leather and Meat Without Killing Animals"

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A Ted Talk by Andras Forgacs entitled "Leather and Meat Without Killing Animals"

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Leather and meat without killing animals

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By 2050, it will take 100 billion land animals to provide the world’s population with meat, dairy, eggs and leather goods. Maintaining this herd will take a huge, potentially unsustainable toll on the planet. What if there were a different way? In this eye-opening talk, tissue engineering advocate Andras Forgacs argues that biofabricating meat and leather is a civilized way to move past killing animals for hamburgers and handbags.