Stella McCartney has a new collaborative initiative with Bolt Threads, a biotech company based in the San Francisco Bay Area that specializes in advancing sustainable materials. The firm develops fibers from scratch based on proteins found in nature, as well as clean, closed-loop manufacturing processes. An example is vegan-friendly silk created from yeast, which will be implemented into McCartney’s work.

“When I first started in fashion design I never thought there would be a day like this, where we would arrive with such an important moment when technology is fused with fashion, one of the most harmful industries to the environment,” said the designer. “Now is the time to search for answers, for alternatives. For me, I’ve always struggled with the use of silk and finding Bolt has been a life-changing and career-changing moment for me.”

The initial product of the partnership between McCartney and Bolt will be a one-of-a-kind gold shift dress commissioned for the Museum of Modern Art’s upcoming design exhibition, “Items: Is Fashion Modern?,” opening October 1 through January 28.

Beyond the exhibition the terms of the collaboration are undetermined. There’s been no monetary investment in Bolt by Stella McCartney or her partner company Kering. Bolt chief executive officer Dan Widmaier said, “Right now, we’re excited to leverage our signature protein-based yarn, inspired by spider silk, within upcoming Stella McCartney collections. As our partnership develops over time, our teams are eager to collaborate on additional technologies and textiles, and explore the possibilities of innovation by working together.”

More than 50 percent of McCartney’s women’s collection is made from sustainable materials, and the brand is vegetarian. She is stepping up the eco message. Her fall campaign was shot in a Scottish landfill. And last month, McCartney revealed that her company had formed an ongoing partnership with Parley for the Oceans, an organization that collects plastic bottles from the ocean and puts them to better use, such as developing Parley Ocean Plastic materials. McCartney is using the yarn on two products: the Adidas by Stella McCartney Parley Ultra Boost shoe for fall and a backpack.