We have already mentioned in our previous articles that vegan leather is often either plastic-based or includes plastic and while it saves the lives of animals, it is most of the time not entirely harmless to the environment.
There is an entire article dedicated to cork leather which I find fascinating, but there are many other plant-based vegan leather materials out there that are worth mentioning: corn leather, kelp leather, piñatex (pineapple leather), apple leather, cactus leather, mushroom leather, and kombucha leather. Yes, the list is not exhaustive, but it is a start that helps us dive into this exciting plant-based leather world.
Corn leather
Corn leather is made from corn leftover from the food industry which itself is a good thing. However, to get the durable and smooth corn leather, this leftover corn is combined with polyurethane. Yes, you got it right, it is plastic. The ratio between corn and polyurethane can range from roughly 50-80%.
Corn is one of the most common crops grown while using monocropping techniques. It means the same crop is grown in the same land year after year which devastates the soil (depletes nitrogen and other important nutrients from the soil). Due to the bad quality of soil, a lot of fertilizers are being used to increase the harvest. This pollutes groundwater and when becomes airborne, creates air pollution. Additionally, corn is often genetically modified (GMO) to be more resistant to weeds and natural pests. In the US most of the corn crop is genetically modified. This of course does not apply when corn is produced organically.
Corn leather is being used to make shoes, purses, and other typical leather products. It is known to be a bit tougher than animal leather.
There are some companies that make sure the corn leather they use comes from a sustainable source (meaning the product was organic, no fertilizers and pesticides used in the cultivation process), but even then the product is not entirely bio-degradable due to the plastic the corn waste is combined with. Let’s hope this will change in the future.
Kelp leather
Kelp is a brown seaweed species that grows in shallow oceans. They require nutrient-rich water with temperatures between 6-14°C. Kelp can grow into dense ocean forests (kelp forests, e.g. by the Norwegian coast) supporting a large number of animals.
Kelp is growing incredibly fast, about half a meter per day. It also absorbs CO2 five times faster than land plants and absorbs other toxic compounds that are responsible for the bloom of different algae. Its growth requires no interruption, no fertilizers, and is entirely natural. It is harvested from coastal waters. The cutting is done without damaging the plant and it actually encourages the plant to sprout more. After harvest, it is dried naturally, making the production process very energy efficient.
The kelp leather production process is patented by the US corporation called Nanonnic Incorporated and the material is called SeaCell. They embed dried and crushed seaweed into cellulose (Tencel) by using nanotechnology. To become what is SeaCell fabric, the same production techniques are being used as for lyocell, just with a percentage of seaweed added. Read more about Tencel here.
Kelp leather has many great benefits. It is flexible, versatile, durable, breathable, light, flame retardant, soft against the skin, absorbs sweat, and has also some health benefits (it contains some antioxidants and minerals that absorb into the skin of its wearer). It is also carbon-neutral, eco-friendly and 100% biodegradable.
Kelp leather is currently used for making textiles for clothing (t-shirts, reusable diapers, yoga clothes, sleepwear, etc.).
Have we found an even or perhaps more superior competitor to cork leather? We may have.
Piñatex
Piñatex or pineapple leather is made from cellulose fibers extracted from pineapple leaves, PLA (polylactic acid, also known as bio-plastic), and petroleum-based resin. It was developed by Carmen Hijosa and is nowadays created by her company called Ananas Anam Ltd.
Piñatex won the Arts Foundation UK award for Material Innovation in 2016 and Carmen Hijosa was one of the finalists of the Cartier Women’s Initiative Awards in 2015.
Piñatex is created from pineapple leaf fiber which is an agricultural waste product. If not used, this waste would be left to rot or burnt. The Ananas Anam LTD website mentions that in making Piñatex, 264 tons of CO2 is saved thanks to not burning 825 tons of waste leaves (not sure within which timeframe).
The leaves are collected in bundles and long fibers are extracted by using semi-automatic machinery. The fibers are then washed and dried naturally (in the sun or drying ovens). Once dried, it goes through a purification process which creates a fluff-like material. This is mixed with polylactic acid (PLA) to create Piñafelt which is a non-woven mesh that forms the base of the Piñatex collection. This all happens in the Philippines after which the material is sent either to Italy or Spain for the final finishing. This consists of coloring and coating the material for which the petroleum-based resin is used. It gives Piñatex its strength, durability, and water resistance.
Approximately 180 leaves (the waste of 16 pineapples) are needed to create 1 square meter of the material.
Piñatex has been described as breathable and flexible, soft and more pliable leather-like material. It is used for making bags, shoes, wallets, watch bands, and seat covers. The textile is being further developed for use in clothing.
Since it is created from a waste product, it does not require additional land, water, pesticides, nor fertilizers. The production process avoids the use of toxic chemicals and heavy metals that are used in animal leather production. However, the material is not bio-degradable as you may have guessed.
Apple leather
Apple leather is created from leftover apple waste from the juice and compot industry. An Italian inventor Alberto Volcan started to develop it in 2004 and after he had created an ecological paper from apple waste, he joined hands with a company called Frumat who is specializing in the recycling of industrial waste. While they had setbacks in the early stages, they finally managed to develop an ecological, breathable, waterproof, and durable fabric. Believe it or not but one of the key stages of the development process was placing vegetable glue made from apple waste through a pasta machine to get sheets that were the base of apple leather. You would really not expect less from an Italian inventor.
During the production process, the apple waste is reduced to powder. Once processed, it is later combined with polyurethane and then coated onto cotton or polyester canvas.
Apple leather is used for the production of clothes, shoes, luggage, and leather goods, but also furnishing accessories, sofas, company gadgets, coatings, and much more.
It is very similar to Piñatex. It is sourced from a waste product and later combined with plastic-based materials to improve its quality. While it is not biodegradable, it is created from renewable sources and the waste they turn into usable products would otherwise end up in landfills or in some cases burned for fuel.
Cactus leather
Cactus leather (or Nopal leather) is made from Opuntia cactus which is also called Nopal in Spanish. It was developed in Mexico by Adrián López Velarde and Marte Cázarez. They are both the inventors of the material and the company behind it – Desserto. It took 2 years of R&D to come up with the patented process of cactus leather production. The material was introduced to the world in 2019 at the International Leather Fair in Milan and was welcomed with a lot of enthusiasm and excitement.
The production process is very sustainable. The material is harvested in an organic cactus farm in the state of Zacatecas in Mexico. Only the mature leaves are picked while keeping the core intact. It means in 6-8 months the leaves will grow back and can be harvested again. The plant requires very little water – the rainwater only is enough. The harvested leaves are mashed and dried for 3 days in the sun. Once the right level of moisture is achieved, the substance is mixed with non-toxic chemicals and attached to a backing.
The material is available in a few different colors: green, red, black, white, and in different shades of blue and green. It can be used to make clothing, accessories, furniture, and car interiors.
Nopal vegan leather is cruelty-free, organic, partially bio-degradable, and as soft as leather. It is also free of phthalates, toxic chemicals, and PVC.
As the material is very new to the market, the main question asked is how long does it last? According to Desserto, it can survive 10 years, or more – depending on the intensity of usage.
Mushroom leather
Mushroom leather in 2021 is still in the phase of development by many research groups and companies in different locations in the world (e.g. U.S, Finland, and Germany).
Perhaps the most talked about and the one with most famous consortium partners (Adidas, Kering, lululemon, and Stella McCartney) is Bolt Threads – a U.S material innovation company based in California. They are marketing a material named Mylo which is made from mycelium. Mycelium is the root structure of filamentous mushrooms. It is a sprawling, infinitely renewable interlaced web that threads through the soil, plants, and other trees.
For mushroom leather production the mycelium is grown in biocreators. It basically means that what happens under the forest floor is being simulated in an indoor controlled environment. The mycelia cells are fed sawdust and organic material while controlling the humidity and temperature among other variables. Mycelium grows into a foamy layer. Once it is harvested, the remaining material is composted. The sheet of mycelium is processed and dyed and becomes eventually the so-called Mylo material. The mycelium grown for Mylo is produced in days. Bolt Threads does not really say what is exactly is used for the processing and finishing, except that these chemistries are intentionally evaluated and selected by using Green Chemistry principles.
The material can be used to make footwear, handbags, wallets, phone cases, and other similar products.
Mylo is not bio-degradable and not plastic-free. However, 50-85% of the end product is bio-based.
Another research group worth mentioning is Finland’s VTT Technical Research group who is also growing mycelium in biocreators and are developing 100% biobased material. You may find a short introduction video about their project here.
Kombucha leather
Kombucha leather (also known as SCOBY leather) is a flexible biomaterial made from a symbiotic culture of bacteria and yeast (SCOBY). It is a byproduct of kombucha tea that feeds on a mixture of vinegar and sugar. It takes about 3-4 weeks to grow the material in the lab.
Once it is harvested and dried, it is molded into shape. It can be produced in any shape and does not require to be sewed together as the pieces will glue stick together and dry as one. Kombucha leather does also not require chemical-based tanning, unlike traditional leather.
This material is relatively new to the apparel industry and the tests have revealed that one of its biggest problems is moisture absorption. It softens the material and makes it less durable. It is also known that cold conditions make it brittle. Scoby leather is not suitable for mass production yet as 3-4 week growth interval is too long and the aim is to find ways to grow it faster in lab conditions.
However, the material is 100% bio-degradable unless treated with strong chemicals that make it waterproof.
It is mainly used for making clothes, shoes, and wallets.
It is incredibly exciting how many different leather alternatives are being created and developed these days from plant-based materials that either grow in abundance or are simply a byproduct of another industry. As mentioned at the beginning of the article, the list above is not even exhaustive and there are other very interesting plant-based vegan leather materials still out there (either in the development or production phase).
What all plant-based vegan leathers have in common and what they also like to use for advertisement is that they are cruelty-free since no animals have been harmed during the harvest and production process. Now, here the thing I would argue with is that while no indirect harm is being done, there are some plants which cultivation definitely indirectly harms animals thanks to the pesticides and fertilizers used that pollute the soil, water, and air.
However, the main source of plant-based vegan leather is often waste or a by-product that would have otherwise just been burnt or left in landfills. That means they are still very environment friendly compared to animal leather production that requires a lot of land, water, and feed plus toxic chemicals. Livestock also emits a significant amount of methane (greenhouse gas) and the feces pollute the air and waterways putting local communities in danger.
The downside of different vegan leather productions processes (with very few exceptions) is the need to use chemicals (different plastics) that make the end product not bio-degradable, yet improve the quality and durability of the material. Hopefully, with more research and development over the years, this will change and we have both very good and durable plus entirely bio-degradable leather products in the market. The demand is definitely there as more and more end consumers are developing environmentally friendly attitudes and making more and more conscious purchasing choices.