Nylon-spandex is the best material for a rash guard.

Yes, a nylon-spandex blend is the way to go.

Nylon is soft, stretches just enough with spandex, and dries quickly without getting clammy. It also holds up well to saltwater, sunscreen, and the occasional wash. Polyester blends are cheaper and more durable, but they feel rougher against skin and can trap sweat. Unless you’re dragging your rash guard across rocks every day, nylon-spandex is the comfortable, long-lasting choice.

If you surf or paddle a lot in harsh sun, look for a UPF 50+ rating—most good nylon blends have that built in. Skip the cotton blends; they hold water like a towel and weigh you down.

Your skin will thank you.