Common materials include recycled polyester blends and polyester/spandex or nylon/spandex blends — for example: 85% recycled polyester/15% elastane, 85% polyester/15% spandex, 80% nylon/20% spandex, and 58% polyester/34% nylon/8% spandex.
Most items are rated UPF 50+, and product descriptions note this blocks roughly 97.5%–99+% of UV rays.
Many styles are pull-on/pullover. Some one-pieces include quarter- or half-back zippers, and a few feature snaps (including crotch snaps) to make changing easier.
Care varies by item: some list machine wash and tumble dry, while many recommend hand wash and line dry or lay flat to dry.
Lining varies by style: some bikini bottoms or pieces are fully or partially lined, while several one-piece rashguards are described as unlined.