Microfiber

Microfiber is polyester (often split with nylon) spun into ultra-fine filaments — finer strands of the same plastic. Cleaning cloths, towels, budget sheets, and couch upholstery are the usual suspects.

The fineness that makes it grippy and absorbent also makes it shed heavily; ironically, cloths sold to clean “without chemicals” are among the most concentrated microplastic sources in a home wash.

Microfiber scores 100/100, whether listed in a composition or detected as a keyword in the product text.

The same weight applies everywhere: a product's score is the percentage-weighted plastic share of its listed fiber composition, and every weight is public.