The synthetic fabric used to make stretchy clothing is commonly referred to as spandex and as Lycra. DuPont created the term Lycra as a brand name for its spandex, and now the terms have become interchangeable. Much like when a person calls all tissues "Kleenex," many people call all spandex "Lycra." Spandex may also be called "elastane," especially in Europe.

The most popular examples of clothing made of Lycra (spandex) include exercise and sports clothing such as bathing suits, wet suits and bicycle shorts. Dance costumes and other sporting outfits often contain the material as well. Underwear, bras, hosiery and leggings often contain spandex, as do pants that stretch or cling to the body. The material is listed on the tag of an article of clothing as spandex, Lycra or elastane depending on the source and location of the material.

The synthetic copolymers used to create spandex are strong and elastic like rubber, but stronger and more flexible. The fabric is often thin but resilient or long-lasting. At high temperatures, spandex will melt like plastic. Spandex is originally white, so colored dyes are added to create a variety of colors. Spandex may also be blended with other fabrics to create varied consistencies and textures.

During World War II, scientists developed alternatives to rubber such as polyurethane and nylon. In 1962, DuPont created a lighter weight and more elastic alternative to rubber (spandex) and named it Lycra. DuPont's Lycra (now under the company Invista) remains the most popular and widespread brand of spandex today.

Elasticity and durability are the major benefits of spandex material. Spandex clothing can be worn in situations when movement is necessary or more comfortable, while other fabrics such as denim or leather restrict movement. Spandex also retains its original shape well, so it lasts longer than many other fabrics, like cotton.

When purchasing clothing, look at the tag to determine what percentage of the fabric is made of spandex (or Lycra). The higher the percentage, the tighter the clothing. Clothing that is 70 percent or more spandex should not be put in the dryer or should be air-dried without heat to prevent damage.