Are Mushrooms the Future of Alternative Leather?

In 2007, Philip Ross, an artist based in the Bay Area, was preparing for an exhibit. It demonstrated his work with “mycotecture,” the creation of materials from the manipulation of mycelium, which is the substance comprising the root structure of mushrooms. Mr. Ross bought mushroom spores from local farmers and coaxed them to grow into a substance he describes as akin to medium-density fiberboard. Preparing for the exhibit, he met Sophia Wang, then a Ph.D. student at the University of California, Berkeley, who helped him produce the show.

Mr. Ross continued to experiment with mycelium, and by 2012, after receiving requests from multiple companies interested in the technology, Mr. Ross asked Ms. Wang to join him in starting MycoWorks to commercialize his mycotecture technique. They co-founded the company the following year, while Ms. Wang was finishing her dissertation.

At the outset “there were three of us in a basement with plywood and plastic sheeting,” said Ms. Wang, who is now the company’s chief of culture. “We were a start-up biotech company, but we were created by artists.”

MycoWorks eventually focused on creating a material that had the look and feel of leather but was free of animal parts. Called Reishi, after the Japanese name for the genus of mushrooms Mr. Ross first used, it can currently be produced in sheets of six square feet. (MycoWorks declined to disclose pricing except to say that it is currently comparable with exotic hides. As the company continues to grow, they added, MycoWorks will be able to offer some at lower prices.)

The company, whose headquarters are in Emeryville, Calif., has obtained more than 75 patents and now has over 160 employees in the United States, France and Spain. It has also secured collaborations with high-end companies like Hermès and, most recently, the furniture maker Ligne Roset and GM Ventures, the investment arm of General Motors.

If it continues to scale up, MycoWorks has enormous potential: The leather goods market exceeded $400 billion in 2021 and is expected to surpass $720 billion by 2030.

Then there’s the global market for synthetic leather materials, which is expected to reach almost $67 billion by 2030, according to Research and Markets, a source for data and analysis. The so-called bio-based leather market, which includes only naturally occurring material, was estimated at roughly $650 million in 2021 by Polaris Market Research. But that number may be too low, according to Frank Zambrelli, the executive director of the Responsible Business Coalition at Fordham University in New York, as well as a managing director at the consulting firm Accenture. “I sincerely believe they are not accurately reflecting market and consumer interest in the category, nor the advances in the technology and quality of the products emerging,” he said.

To date, many of the leather alternatives are made from the plastics, polyurethane or polyvinyl chloride (better known as PVC), sometimes resulting in the derisive term “pleather.” But the more substantial issue is that those using plastic are generally environmentally unfriendly and don’t provide a sustainable option.

In contrast, MycoWorks “can achieve the same quality and performance as animal leathers without the need for any sort of plastics,” Matthew Scullin, MycoWorks’ chief executive, said at a temporary exhibition showroom in New York in the spring. Now too large to rely solely on local farmers for its supply of mycelium, the company has its own strains which “we basically keep in cold storage,” Mr. Scullin said.

The process starts by combining the mycelium with waste from sawmills in trays; as the sawdust decomposes, the mixture begins to develop into a thin sheet. The material can then be customized to meet clients’ specifications, including specific textures, and can include the addition of other fibers, like cotton. The Fine Mycelium, the trademarked name for its patented technology, is then finished by outside tanneries. (The tanning process does not use chromium, historically one of the most polluting parts of leather manufacturing.)

Because the process for creating Reishi has only a few steps, Mr. Scullin said, it has a “low impact” on the environment. In addition, he said, while animal hides vary in size and texture, Reishi is more consistent and predictable for clients.

In August, MycoWorks broke ground on a 150,000-square-foot plant in Union, S.C. Upon completion by the end of 2023, it will start producing at scale — several million square feet of Reishi per year. The construction is supported by new investments. MycoWorks closed on $125 million in new funding in January. The new factory will allow the company to meet increasing demand; Mr. Scullin says that it has had thousands of inquiries from potential clients.

One client that has already incorporated Reishi is the fashion house Hermès, which styles and tans the fabric (which it calls Sylvania) to use in its Victoria handbags. (The company declined to comment on how much it purchased or the price of the bag, which is no longer featured on their website, when compared with one that used leather.)

Nick Fouquet, a designer hatmaker based in Venice, Calif., who is popular among celebrities, used Reishi in some of his hats this year. “I asked one of my seamstresses and she couldn’t tell the difference between Reishi and real leather,” he said. He produced 50 bucket hats made entirely of the MycoWorks material and, priced at $810, they sold out. He said he hoped to use the fabric again in future seasons.

The automotive industry also offers a huge opportunity, since, Mr. Scullin said, car manufacturers are the second-largest-user of leather, after footwear. Inquiries ramped up last year as carmakers began introducing new electric vehicles into the market, he added. The collaboration with GM Ventures, announced Oct. 18, “aims to advance the development of sustainable automotive materials,” Wade Sheffer, managing director of GM Ventures, said in a statement. (The carmaker declined to disclose the size of its investment.)

While Mr. Scullin would not provide any further details, he said the agreement “is intended to change not only the sustainability profile of cars but also to modernize the supply chain for these materials,” so that they can get to market faster. To that end, he said, he envisions starting new plants to service the automotive industry.

MycoWorks has competition. Bolt Threads, based in California, is also producing a leather like material made from mycelium and is attracting high-end clients at an impressive rate. Bolt is working with Stella McCartney, known for her avoidance of animal products, as well as Adidas, Lululemon and Mercedes. Other material scientists are experimenting with bio-based fabrics, including those incorporating pineapple and cactus.

The companies working with mycelium, Mr. Zambrelli said, “are not trying to duplicate what an animal hide does but are creating something that has the softness and resiliency of leather, but something that is, fascinatingly, also more controllable.”

And mycelium continues to be used in the visual arts, Mr. Ross, the founder, who is now chief technology officer, said. At Mycoworks, Ms. Wang said, “the practice is most evident in our product design and prototyping. That’s how people here are really getting creative.”