Recycled polyester is commonly sourced from post-consumer plastic bottles and sometimes industrial plastic waste. Processing is widespread across Asia, with additional recycling and fiber production capacity globally. The main challenges are traceability of input streams, quality variations, and microplastic shedding in use. Certifications like GRS/RCS can verify recycled content and chain-of-custody; GRS also addresses chemicals and social compliance. Recycled polyester is used in outerwear, bags, athleisure, and linings.