Nylon (Polyamide)

Nylon — labeled “polyamide” or “PA” in Europe — was the first fully synthetic fiber, invented in 1935 as a silk substitute. It is a crude-oil-derived thermoplastic prized for strength and stretch, which makes it the default in tights, swimwear, backpacks, windbreakers, and umbrellas.

Like all synthetics it sheds microfibers in the wash, and swimwear sheds directly into pools and open water. Regenerated versions (Econyl) divert waste like fishing nets but produce the same plastic fiber.

Nylon and polyamide score 100/100. A swimsuit at “82% nylon, 18% elastane” scores 100 — both fibers are fully synthetic. Recycled nylon scores the same, with the recycled claim shown separately.

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.