Stella McCartney has incorporated Spiber’s Brewed Protein™ fiber into its Winter 2026 collection, unveiled on the runway at Paris Fashion Week.

Spiber and Stella McCartney have collaborated for over four years, advancing material development and exploring the most suitable expressions for the brand’s collections. Known for challenging the notion that luxury must rely on animal-derived materials, Stella McCartney shares a vision of redefining what luxury can represent. This collaboration reflects a joint commitment to expanding that definition through innovation in materials.

As a significant share of fashion’s environmental impact originates from raw materials, reducing impact at scale requires rethinking how those materials are produced. Spiber’s Brewed Protein™ fiber enables protein-based materials to be created through fermentation rather than livestock farming, representing a transition from pasture-based production to precision fermentation and a structural evolution in material manufacturing.

The Winter 2026 collection features exceptionally fine Brewed Protein™ fiber measuring 12 to 14 microns in diameter, contributing to its distinctive texture and smooth, refined hand feel.

Garments incorporating Brewed Protein™ fiber will be released as part of the Stella McCartney Winter 2026 collection. Further details regarding retail availability will be announced in due course.

Going forward, Spiber will continue working alongside Stella McCartney as a partner advancing the brand’s exploration of new possibilities in fashion through next-generation materials, while pursuing a balance between creativity and more responsible production.