Scientists in China have synthesized spider silk from genetically modified silkworms, producing fibers six times tougher than the Kevlar used in bulletproof vests. The study, published September 20 in the journal Matter, is the first to successfully produce full-length spider silk proteins using silkworms. The findings demonstrate a technique that could be used to manufacture an environmentally friendly alternative to synthetic commercial fibers such as nylon.
We are probably near the minimum already, at least in terms of area/volume (rather than mass). Too few fibers and you’re wearing a mesh net, and not a tee-shirt.