Polyester has undeniable benefits, says Ryan Thompson, Patagonia’s manager of materials R&D for the technical knit, naturals and trim categories. “In historic alpine insulation systems, the material of choice was almost always wool,” says Thompson.
https://www.patagonia.com/stories/what-were-doing-about-our-plastic-problem/story-72799.html
https://www.patagonia.com/stories/what-were-doing-about-our-plastic-problem/story-72799.html