If you select a nice fabric and diligently follow care instructions, a swimsuit should be able to stand the test of time. Right? Not always. According to Nicole, polyester is the prime pick when it comes to durability. "Polyester maintains its shape and holds colour in dyes and prints," she says. Nylon and spandex blends are also good fabrics to keep in mind — ideally, you're looking for material that uses high-quality elastic.