Materials innovation startup Bolt Threads introduced its second biomaterial today – a leather made from mycelium, the roots of a mushroom.
The new leather, which it calls Mylo, will debut on a bag by designer Stella McCartney that will be shown in the Victoria and Albert Museum’s “Fashioned from Nature” exhibit, which opens April 21 in London. It will offer its own bags made of the new material for preorder beginning in June.
“We were looking for the right point to show the world that we are more than just spider silk,” Dan Widmaier, Bolt Threads’ cofounder and CEO, told Forbes in a telephone interview.
Emeryville, California-based Bolt Threads, which has raised more than $200 million in venture funding from Formation 8, Baillie Gifford, Founders Fund and others, launched in 2009 with the ambitious goal of developing synthetic spider silk, a material that’s stronger than steel but softer than a cloud. That’s a tough problem, and many others have tried and failed to do it over the years.
But Widmaier, 37, who had started working on the problem while doing his Ph.D. in chemistry and chemical biology at the University of California, San Francisco, cracked the code. After studying spiders – at one point he and his cofounders had an office full of them spinning webs on hula hoops – he developed a synthetic spider silk from proteins produced through fermentation using yeast, water and sugar, a process that’s oddly similar to making beer. Bolt Threads’ fiber is designed to mimic dragline silk, the filament that a spider extrudes when it rappels. Last year, it debuted its first product, a necktie with a retail price of $314, and it followed up with a hat priced at $198. Bolt Threads has since partnered with Stella McCartney and Patagonia, and also acquired Best Made Co., an outdoor apparel company, which gives it the ability to sell its own products to consumers directly.
While the synthetic spider silk is cool and took years to develop, Widmaier’s vision was always larger than just that one material. “We have made thousands of things in the research lab at tiny scale,” he said. “We will keep rolling out new versions of the products you are seeing with Microsilk and Mylo, and other products as well.”
With the world population at 7 billion people and growing, and increasing numbers of middle-class consumers shopping, the need for sustainable fashion has become intense. Most faux leathers are made from plastic-based materials, which don’t feel the same as leather and result in a similar waste problem to other petroleum-based substances. Mylo is not only a bio-based synthetic material that can be grown in a small space without the environmental impact of large numbers of cattle, but it also can be colored with tea, which has long been used as a natural dying agent due to its strong tannin content. Quantifying the environment impact through a full life-cycle assessment has yet to be done, however, as the project remains in its early days, but Bolt Threads plans to do one after it scales up. “We’re focused on this idea of a new materials revolution,” Widmaier said. “We have a real belief that there is a need in the world for better materials that are better performing and sustainable for a growing population and growing middle class.”
Bolt Threads didn’t develop the new leather on its own, but partnered with another startup, Ecovative. Green Island, New York-based Ecovative had developed the mushroom root technology for packaging that could replace Styrofoam, making a dent in the problem of packaging waste that piles up in landfills and oceans. Ecovative cofounder and CEO Eben Bayer – an alum of the Forbes 30 Under 30 list – had begun working with mycelium in 2009. While still in school, he grew mushrooms under his bed for an early project; last year, Ecovative produced 1 million pounds of mycelium materials.
In the fall, Bayer and Widmaier began talking about how they could work together. While Ecovative had developed the mycelium materials, it did not have the ability to create its own branded products for consumers. “Our strengths are around the research and development,” Bayer said. “I see the benefit of bringing these innovations directly to consumers.”
Bolt Threads’ own Mylo bags, designed by an East Bay design shop with a history of working on leather and synthetic materials, will debut for preorder in June. They will be priced in the hundreds of dollars (Bolt has yet to set an exact price), equivalent to the costs of other premium leather bags. Stella McCartney does not currently have plans to launch the Mylo bag commercially. By email, McCartney said that her brand had long been focused on sustainable fashion and alternative materials. “Once you take that technology and innovation and you marry it with luxury fashion and design and creativity, there’s no end to what magical madness you can create,” she added.
Over time, the Mylo material could be used to create shoes or other apparel or upholstery, as well as bags. While the market for textiles is far larger than that for leather, the ability to produce Mylo at a similar price point to the material it replaces makes it especially interesting. The next big question for Bolt Threads will be how to scale up its production, and that’s something that Widmaier has been thinking about a lot. As he says: “For me, as a technology aficionado, nothing irritates me more than having the idea and never seeing it turn into reality.”
