It is quite amazing that the earliest swimwear material was nothing in the early centuries. The Greeks and Romans would swim in the nude, which continued for hundreds of years. Men continued to swim in the nude until it was banned in 1860. This is when swimwear was invented. They called it a bathing costume and it was just a pair of knee length pants that was pink and white striped. Women until the 17th century did most of their bathing in a spa or bath, away from the men. They may have started bathing in the nude but in the late 17th century they began to wear swimming costumes. Even though most men wore drawers and waistcoats, women were required to wear a long bathing outfit that was made from a yellow canvas material. It would not stick to your skin, so the body would not be seen.
19th century swimsuits
By the 19th century, the bathing costume was geared towards being modest, especially when it came to girls and women. Because of this most bathing costumes were good at concealing any type of racy parts of a woman such as their legs or ankles. So they began to use wool or flannel which was a really thick fabric and was great for concealing the body. The reason for these materials was a win-win for the makers. It preserved modesty and the heavy material helped to defend people from the chilly waters of the English seas. The use of this material continued until about the early 20th century. It was believed that it was great for swimwear because it was long lasting and would resist dirt.
Latex and spandex
Then in 1925 a stretchy type of material called Latex was introduced. It was made from a stretchy type of yarn that had an elastic core that was wound in with silk or cotton threads. It can be one of the more preferred materials for a very long time. This type of material was used up until the 1950s when Nylon material showed up. Then in 1958, the production of Spandex caused swimsuits to become more revealing and more form fitting. Since the 1960s the styles were really altered as it went under a lot of modifications. In the 1980s and 1990s, a trend of being lightly covered so you could develop a good tan. Because of the worries and warnings about developing skin cancer minimized the recognition of these items.
Now there are swimsuits that have been made to be high tech, which means it lessens drag and helps to enhance speed. There are a lot of different styles now that come in polyurethane which helps to put the swimmer in great form. It prevents the skin from causes resistance. This in turn helps to increase velocity for athletic swimmers.