a talk with Laurens de Meyer


Laurens de Meyer gives his vision on leather and its alternatives.

Who is Laurens de Meyer?

I am an engineer with a passion for sustainability and nutrition. A passion that I have been combining since my student days, to make our society more sustainable. Currently, I am working as a policymaker for sustainable nutrition and agriculture at 'Bond Beter Leefmilieu'. Also, I wrote two books: 'Wat w(eten) we?' and 'Moet er nog vlees zijn?' (What do we eat/know? and Should there still be meat?). Because of my work on sustainability issues and my speciality in livestock farming, I enthusiastically said yes to Lies Mertens' request to give my vision on leather and its alternatives.


Leather is a product that is as old as our civilization. The Egyptians were already using leather objects. Due to its qualities in terms of strength, versatility and appearance, leather is still an enormously widely used product. Annually, more than 2,200 square kilometres of leather are produced. That is about 14 times the surface of the Brussels region.

This leather comes from animal skins. In principle, you can make leather from all types of animal skins. Most of the leather production comes from cows, sheep, goats or pigs. Some animals are bred specifically for their hides, but most are a by-product of the meat and dairy industry. Thus, as long as meat and milk are eaten, hides will also be available. Using these skins to make high-quality materials such as leather is in keeping with a sustainable, circular economy. Letting them go to waste or using them for inferior applications than leather would be a shame.

What cannot be denied is that this animal production is associated with a high environmental cost. Today there are more than 1.5 billion cows, 1.2 billion sheep, 1 billion pigs and 1 billion goats on our planet. If you let all these cows do a conga line around the equator, you can circle the earth 90 times. This enormous herd of livestock causes the rainforest's disappearance, enormous water consumption, and greenhouse gas emissions. Animal production is responsible for 14.4% of the global greenhouse gas emissions. We will have to breed fewer animals in the future, reducing the supply of hides in the long term. In terms of animal welfare, too, there is a lot to be said for the plea for fewer animals.

Animals do remain an essential part of our agricultural system. They process waste streams from the food industry, graze soils that are not suitable for other agricultural uses and ensure healthy soils. Animals - and their skins - will therefore continue to be available for a long time. Nevertheless, alternatives will remain important in the future. More about that later, but first we will dive deeper into leather production from animal skins.
Step one to speak of sustainable leather is to ensure that they come from Europe and that they are a residual (/by-) product from the meat and dairy industry. Why in Europe? Despite the existing flaws in our livestock farming today, Europe is a frontrunner globally in terms of sustainable production. For example, a cow in Flanders emits up to 6 times less methane than one in Latin America. By opting for European leather, the transport kilometres between slaughtering, tanning and making the leather goods are also minimized.

To chrome or not to chrome

Tanning is the process of treating animal skins with products to make leather. Skins are made up of protein collagen. The tanning process ensures that this collagen does not rot and becomes a solid material. There are two commonly used processes: with chrome or with vegetable tannins. The latter can be compared to tannins in red wine, except that when tanning they do not come from the peel of grapes but from tree bark.

The vegetable tannins and the chrome do the same with the collagen in the leather: they make a sturdy product that lasts a long time and is resistant in all weathers. Yet there are also differences. Chrome tanned leather is more resistant to moisture and heat. It is smoother, retains its colour better and can be coloured much more diverse. Leather tanned with chrome is, therefore, easier to maintain and lasts longer.

The great advantage of using vegetable tannins is that it is a much more environmentally friendly production process. The wastewater is easier to purify. When using chrome, additional purification steps are required. The latter is possible without environmental pollution, but this does require extra attention. It is therefore vital to choose European tanneries that are certified for their environmentally friendly working method. Europe also has one of the strictest environmental laws in the world.

Besides the European legislation, additional certification remains essential, so you can be sure that the production process goes one step further in terms of sustainability. Specifically, for the leather production process, this certification is provided by the Leather working group. For finished products, the 'leather standard’ of OEKO-TEX is the most important. The leather working group is a collaboration between companies and organizations that provide technical advice to tanneries to continuously take steps to make production more environmentally friendly. They only certify tanneries that work according to the highest environmental standards in water, energy and material use. Lies Mertens only uses leather with a silver or gold certification. This way, they can be sure as a producer that your leather's environmental impact is minimized, regardless of whether it is tanned with chrome or vegetable tannins.


Let's go back to the original material, the skins. More and more alternatives are emerging that can replace the use of animal skins. And here too it is a nuanced story. You have both more sustainable or harmful options. Broadly speaking, you have three types of alternatives: synthetic leather, vegetable leather and cultured leather.

Although synthetic leather does not involve animals, it is not a good thing for the environment. Usually, plastic Polyvinylchloride is used (PVC). Its production is very polluting and is based on fossil resources such as natural gas and oil. Also, it contains many other chemical components, some of which are associated with endocrine-disrupting properties. Finally, it is almost impossible to recycle. So, in the end, it goes to landfill or incinerators. Such materials also cause the known microplastics. Replacing genuine leather with synthetic leather is, therefore, a step backwards for both the environment and your own health.

What is more interesting are vegetable alternatives to leather. Plants also have skin that can be used for leather production. The most famous example is leather made from cork. Cork is the bark of the cork oak, an oak species that mainly grows in southern Europe. The bark is harvested every 9 years from trees that remain productive for up to 300 years. After harvesting the bark, the trees are extra motivated to make their bark again. In doing so, they extract up to 5 times more CO2 from the air than usual, thus helping to combat global warming. Unfortunately, the supply of cork remains relatively limited. It is a much sought-after product for other applications such as wine corks and floors. And I am sure that Lies Mertens does not want to be blamed for a shortage of wine corks ...

Save for a rainy day

Even better is the use of residual products that cannot be used for anything else. Some alternatives use pineapple leaves, apple or grape leftovers. Similar to animal hides, they are a by-product of an existing industry. When pineapple is harvested, the leaves are left behind or burnt. These contain strong fibres that, after processing, are woven and processed into a product with similar properties to leather. The woven fibres only resemble leather through treatment with resins and a small amount of plastic. It is still not 100% natural, but it is already a huge step forward compared to pure synthetic leather.

Even more exciting and closer to home is the production of VEGEA. In 2014, an Italian architect and a biochemist came up with the idea to use residual flows from viticulture as raw material. After pressing the grapes, the skin, seeds, and stems of the grapes remain. These contain fibres and natural oils that have turned out to be the perfect starting material for vegetable leather production. This way, your glass of wine helps with a pleasant Friday evening and contributes to a better world. Since their inception, VEGEA has won one award after another. In 2017, they won the Global change award. The European Parliament praised them as one of the best European start-ups of the new millennium. Lies Mertens is currently researching the use of this material to develop a vegan line. Before they start working with it, they test the strength, maintenance and wear of the material. If it has the same properties as classic leather, it will undoubtedly produce a nice line.

In Belgium, they are working on a similar alternative as well. But then starting from surplus apples or pears. We have quite a few of those. Annually, about 100,000 tons are not sold, and that’s only in Belgium. These are apples or pears that are too big, too small or misshapen. A project is currently running at UCLL College to turn these surpluses into 100% vegetable leather with only natural additives. This product is still in its infancy. It will surely take a few years before a usable product is produced. Yet, when the researchers succeed in their intent, we will acquire a fully circular and local alternative to animal leather and that from our own soil.

New technology hits out

A little further in the future, another alternative emerges, i.e. Biofabricated leather. That is genuine leather but made without an animal. How? Yeast cells are genetically modified to produce collagen. The same protein that genuine leather is made of. This collagen is then purified and composed into a product that, after tanning, is similar to leather from animal skins.

It may sound like science fiction, but the process itself is not that different from brewing beer, for example. Only the yeasts do not produce alcohol but collagen. The big advantage is that you have exactly the same product as leather, but without the animal. This way, you can significantly reduce the negative environmental impact that comes with animals and animal suffering is wholly avoided. Greenhouse gases, water and land-use, can decrease by up to 90%. Another advantage is that entirely new materials can be created, resembling leather in look and feel. But at the same time, they have completely different properties in terms of structure or strength.

It remains to be seen how long it will take before these products are competitive with ordinary leather. In 2017, the first T-shirt made with this material was exhibited at the MOMA in New York by the American company Modern Meadow. Currently, the production process is still in its infancy and is very expensive. But it will undoubtedly revolutionize the leather world in the long run.

Long shall they live

At least as important as the origin of the materials, is the lifespan of a product. The most durable product is the one that lasts a long time. You don't have to replace it at every turn. An interesting concept is the "environmental cost per wear". This represents the environmental impact of a product, expressed in function of the lifespan of your product. Chrome tanned leather is an excellent example of this: the production process of chrome-tanned leather requires more attention to environmental measures; however, it does produce leather with a long lifespan. Suppose you manage this process well and get products that last for years longer. In that case, your total environmental impact will drop considerably.

Especially in the fashion world, things are going wrong here with the expectations created by fast fashion. Collections are released faster and faster, resulting in mountains of waste. This is also the case in the world of leather goods. This is even more a shame because leather is a perfect product meant to last for years. This is also what makes Lies Mertens unique. They choose to distance themselves from the treadmill of seasonal collections. Each model is based on a timeless design. And thanks to the traditional and manual production process, you get a bag that can be perfectly restored. The combination of all this ensures bags that can be used day in, day out for years to come. Which is perhaps the most important basis for being able to speak of a truly sustainable product.

What do you take with you in your Lies Mertens bag?

- Leather is a circular raw material for manufacturing long-lasting products.

- European leather produces fewer greenhouse gases than leather from other continents and is made according to the strictest environmental standards.

- In addition to the production process itself, monitoring the process is particularly important for the corresponding environmental impact. For example, chrome-tanned leather is not always worse than vegetable-tanned leather.

- Alternative materials are on the rise and will make the sector more sustainable in the coming years.

- Not all vegan alternatives to leather are better for the environment

- Fast fashion is never environmentally friendly, long-lasting fashion is

- A glass of wine not only results in a pleasant Friday evening but also contributes to sustainable plant-based bags.