Bathing suits come in many fabrics including cotton, nylon, polyester, spandex and blended combinations of these fabrics. You cannot shrink bathing suits that are made of nylon, polyester or spandex. The spandex is comprised of small threads of elastic. The elastic will melt and deteriorate when exposed to high heat. Nylon can also be damaged by high heat. Swimsuits made of mostly polyester will not shrink as well. Many bathing suits are now made of cotton and cotton blends. You can shrink an all-cotton swimsuit and cotton blend fabrics. Swimsuits made of 100 percent cotton will shrink more than a cotton blend suit. To determine the fabric type, refer to the garment's tag, which is typically affixed to one of the seams.
Things You'll Need
Fill a sink with warm water.
Pour a few drops of laundry detergent into the water.
Hand-wash the bathing suit in the soapy water.
Rinse the bathing suit under a stream of warm water. Squeeze out the excess water, but do not twist or wring out the bathing suit.
Place the swimsuit in the clothes dryer and run it for 60 minutes or until dry. Use high heat on an all-cotton bathing suit. Use low heat for cotton blends. When you remove it from the dryer, the bathing suit will be slightly smaller.
Check the bathing suit's tag to determine the fabric type and to read the fabric care recommendations. Do not wring out or twist the bathing suit. This will stretch it and damage the fibers in a spandex suit. You'll need to shrink the bathing suit after every use.
Do not use bleach on your swimsuit. Do not place spandex bathing suits in the clothes dryer. Always use low heat for nylon and nylon blends.