A paper swimsuit is a swimsuit which has been specifically designed for competition, and while not actually made from paper, such suits are often paper thin. Racing suits have a number of design features which distinguish them from ordinary swimsuits, and for competition swimmers, it is crucial to make sure that such suits are fitted properly to ensure that the swimmer will perform at her or his best during competition. Needless to say, such suits are often lacking in the modesty department, because the focus is on performance, not looks.
A typical paper swimsuit is extremely thin, and typically single-layered, and it is very stretchy. Paper swimsuits are designed to be very tight, and they are worn snug on the body. The tightness and thin design provide minimal resistance in the water, allowing the swimmer to swim faster. For casual swimmers, a small reduction in resistance might not seem like a major improvement, but competition swimmers know that every fraction of a second counts, and they take their swimsuit selection very seriously.
For events like the Olympics, swimsuit manufacturers often unveil a special paper swimsuit designed just for Olympic athletes, with design features which are intended to make it into the best possible swimsuit for competition wear. In cases where national teams have sponsorship deals with swimsuit manufacturers, they have been known to violate their contracts in order to swim in the best racing suits, and sometimes controversy erupts, especially when teams eschew their national companies in favor of foreign firms with better racing suits.
For people unfamiliar with wearing a paper swimsuit, trying one on can be a bit uncomfortable. The suits are meant to be very snug, and they generally do not leave much to the imagination. The lack of a double layer or modesty paneling can also make wearing a paper swimsuit a bit awkward for people who are concerned with modesty; competition athletes are usually so focused on performance that they do not pay very much attention to their appearance when wearing their racing suits.
Athletic stores which specialize in swimwear typically carry a range of racing suits for people to examine and try on, often with verbose labels making all sorts of claims about the performance improvements which can be enjoyed by purchasing specific swim products. It is a good idea to try on several suits to get an idea of comfort and fit, and sometimes shop clerks can offer advice or assistance for people purchasing their first racing suits.