Nature holds the secrets to revolutionizing fashion: novel eco-friendly textiles with customized functionality. Bolt Threads is using biotechnology to design protein-based materials at the molecular level, starting with spider silk. For decades, researchers have attempted to make commercial quantities of spider silk; hear how Bolt is working to scale up this technology. Its platform for customizable natural materials comes at a critical time, as we begin to understand the environmental and health implications of synthetic microfiber pollution.