Spandex doesn't contract under normal washing conditions, but if you can heat it up to just over 180-degrees Fahrenheit, it is possible to shrink it. As a synthetic polyester-polyurethane fiber, DuPont originally created the product under the brand name Lycra as a replacement for rubber.
Spandex has the ability to stretch to many times its length and then snap back to its original size without any loss of elasticity. Clothing made from spandex is intended to fit snugly, have improved movement and drape while holding its shape.
Read the tips listed on garment or item care labels as the other fabrics may be affected if you attempt to shrink spandex. Care tags usually indicate to wash items that contain spandex in lukewarm water, placing them on a flat toweled surface to dry. But when you wash and dry these items with high heat, you might shrink your garment up to 5 to 10 percent.
Fabric that contains spandex always contains other fibers as well. Spandex is combined with other natural and synthetic fibers, such as cotton and polyester. Most garments contain about 2 to 10 percent spandex. Before attempting to shrink your garment with heat, pay attention to the item's fabric content.
Dyes in garments containing natural fibers like cotton may fade or bleed when exposed to heat, whereas the dyes in polyester or other synthetic garments will remain vibrant.
Never try to shrink garments containing spandex with an iron. The spandex can become gummy, and this actually stretches the item instead of shrinking it.
Shrink Spandex in the Wash
A combination of a hot-water wash and rinse along with the high-heat setting on the dryer can shrink some garments or items that contain spandex.
Things You'll Need
Step 1: Wash It
Wash one garment at a time since different garments may shrink at different rates. Choose the machine's smallest water level setting, and set the water temperature to its hottest water option. Some washing machines automatically have a cold rinse cycle after a hot wash. This is designed to relax the fabrics of your garments, but that is the opposite of what you want to happen. If your machine rinses the wash with cold water, then skip the rinse cycle and advance the machine to the spin cycle after washing. Pull your garment out of the washer as soon as the spin cycle is finished.
Step 2: Dry It
Place your garment inside a pillowcase. Tie a knot at the top or secure it closed with ribbon tie. This keeps the garment bunched up and prevents the fibers from stretching as the garment spins in the dryer. Set the dryer to the highest heat-level setting. Once your garment is dry, keep it in the dryer for an additional 10 minutes.
Step 3: Try It On
Pull your garment out of the dryer and immediately try it on. Be careful, because any buttons, snaps or zippers will still be very hot. If your garment still has not shrunk to the size you desire, then repeat the entire process. One you have shrunk the spandex, rewash the garment as you would normally to remove the detergent if you had to skip the rinse cycle.
Proceed with caution if your garment contains cotton or other natural fibers that shrink easily in the wash.
When spandex does shrink, it shrinks in both directions: length and width.