Founded: 2009

Headquarters: Emeryville, California



Bolt Threads, originally named Refactored Materials, was founded in 2009 by Dan Widmaier, David Breslauer, and Ethan Mirsky to use biotechnological innovation to create materials. Dan Widmaier initially developed this idea during his Ph.D. in Chemical Biology. The company has since grown to a team of nearly 100 employees.

The company’s first material was their spider silk product Microsilk (Profile of Bolt Threads - Microsilk). They recently expanded into making alternative leather from mycelium and began producing their B-Silk Protein for use in cosmetics and personal care. 


Mylo is a leather alternative made from mycelium.


Production process: Mycelium

Bolt Threads licensed technology from the New York-based company, Evocative, which originally used mycelium to create packaging as an alternative to styrofoam. Like other mycelium leathers, Bolt Threads grows the mycelium for Mylo on agricultural waste. By controlling temperature and humidity, they control the growth into a dense mat of interconnected cells. The mycelium mat is tanned and dyed without chromium and then imprinted with a pattern to create the final material.


Mylo is likely more sustainable than animal leathers and petroleum-based alternatives in a number of measures. Mylo can be produced in a matter of days compared to years for animal leather. The process of making Mylo does not involve raising livestock, and likely uses less water and fewer chemicals than animal leathers and petroleum-based alternatives. The company intends to produce a lifecycle analysis of Mylo prior to large scale commercial rollout.


Bolt Threads states that Mylo has a soft, warm feel and is durable and abrasion-resistant.



Bolt Threads collaborated with Stella McCartney to create a prototype of her iconic Falabella bag, made with Mylo.

Bolt Threads’ first commercially available bag made with Mylo was in collaboration with Chester Wallace and funded through a Kickstarter campaign in October 2018.

In 2020, Bolt Threads announced the formation of their Mylo Consortium, which includes adidas, Kering, Lululemon, and Stella McCartney, through which they intend to introduce new products to the market in 2021. 

Images from Bolt Threads.

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