Sustainable textile innovations: mushroom leather

In view of resources dwindling fast and natural fibres like cotton being resource-intensive to process and petroleum-based fibres like acrylic, polyester, nylon and spandex not being the most environmentally friendly, it is about time to look for sustainable alternatives when producing fibres and fabrics. In this series, FashionUnited explores the sustainable alternatives and textile innovations that are currently being pursued all over the world.

German company ZVNDER (pronounced 'tsoonder') specialises in the production of accessories like wallets, neck pouches, caps and watch straps made out of tinder fungus 'leather'. The tinder fungus or horse fungus (Fomes fomentarius) lives on dead or weak trees, often for years, and produces very large polypore fruit bodies that are shaped like a horse's hoof.

Tinder fungi typically continue to live on trees long after they have died, thus changing from parasites to decomposers; birch, beech and oak are common host trees. The polypores can reach a diameter of up to 30 centimeters. Earlier, thin strips of the inner spongy layer were cut and used as tinder, giving the fungus its nickname.

Mushroom leather has many advantages

Mushroom leather is organic, gluten and chemical free and has a marbled, velvety surface. It is only visually similar to animal leather but is a vegan product with highly absorbing, antibacterial and antiseptic properties. The high amount of air gives the mushroom leather its lightness and at the same time, has an insulating effect.

The material is sourced in Transylvania, Romania, a densely forested region where many tinder sponges grow. Accordingly, producing amadou - the spongy material derived from Fomes fomentarius - has been practiced for generations here and ZVNDER relies on this knowledge and the unique qualitative production of local family businesses. The mushrooms are harvested by hand, thus in a nature-friendly way and dried for up to one year. Then, they are peeled and processed by hand in an elaborate process.

"The family businesses receive certificates for collecting the mushrooms. As a result, the fruiting bodies of the tree fungi can be harvested with care and the preservation of the species is ensured. During processing, no chemicals are used. The resulting waste materials during processing are used, for example, as a smoking product in beekeeping", explains ZVNDER.

In a small studio in a suburb of Berlin, the handmade tinder sponge leather is then processed further, keeping the unique properties of the material in mind and adapting them to fit the product requirements. For example, natural absorbency is developed further to protect the tinder sponge leather from moisture and to make it more durable. In addition to the production of composites from biotech and mushroom leather, various coatings are used.

All parts of the tinder fungus can be used

ZVNDER believes in a holistic usage of the tinder fungus as a resource and thus , there is no waste. Even rest materials can be used to make fibres, which make excellent insoles. "The highly absorbent fibers can absorb a lot of moisture in the shoe. In direct contact with the skin, there have been successful tests to improve athlete's foot. Even as watch straps, the fibers can prevent skin irritation of people suffering from eczema," says ZVNDER.

The healing properties of the tinder sponge have been known for centuries and have recently been confirmed by a study demonstrating the medicinal effect of the 1,3 / 1,6-β-D-glucan-chitin-melanin portion of tinder sponge fibers. Tinder sponge is already used for cosmetics and dietary supplements as a remedy for atopic dermatitis and to strengthen the immune system.

Shoes made of mushroom leather: cooperation with nat-2

„The natural, vegan and individual characteristics of tinder fungus leather make each product unique“, promises the start-up. Thus, ZVNDER does not offer mass produced articles but constantly works on expanding its product line - for example with a sneaker made out of mushroom leather made in collaboration with German firm nat-2, which recently started its fungi line.

"'Mushroom leather' is unique in its vintage look and unbelievably soft in its feel as well. By using the material from both sides interesting contrasts and combination become possible," says nat-2 about its new shoe. The elementary material stems from ZVNDER, which then gets combined with other high quality, innovative materials sich as eco-cotton frottee, microfibre suede from recycled PET bottles, real cork insoles and real rubber outsoles. Production is done by hand by a small family manufacturing unit in Italy.

For future cooperations, ZVNDER cautions potential partners to keep in mind that mushroom leather is a niche product and the quantity of articles thus limited. "As with leather production, there are different sizes and qualities of leather pieces. The patterns are laid by hand during the production process", adds ZVNDER.

ZVNDER was founded and 2017, based on Nina Fabert's master’s thesis of developing a vegan leather made from mushrooms, looking at traditional production methods. Her work was featured in 2016 at the prominent Martin Gropius Bau Berlin exhibition hall and has been awarded a scholarship by the Elsa Neuman Foundation in 2015. This year, it has been nominated for the German Design Award.

Photos: all ZVNDER except for tinder fungus: George Chernilevsky / Wikipedia and nat-2 fungi line: nat-2