ProSpin® is a patented core-spun yarn, made by Cone Mills, featuring a polyester core wrapped with a pima cotton blend (55% cotton/45% polyester (core spun)). The result is a fabric which offers the aesthetics of cotton with the performance of a synthetic. ProSpin is naturally wrinkle-resistant and over twice as strong as wrinkle free cotton fabrics with resin treatment. Frequently used for shoeuppers .