Rayon is a manufactured product made from natural wood fibers, making it a cross between a natural and synthetic fabric. Because rayon is manufactured in a variety of ways, the care varies depending on the type of rayon. There are essential four types of rayon available to the mass market, and each type has its own care requirement. Before drying an item made of rayon, check to see what type of rayon it is. If you don't know, err on the side of safety and dry clean the item.
Standard rayon is most commonly found in clothing and home décor items. It is also known as viscose rayon, and has a silky drape and high sheen; the individual fibers are untreated. Because of this, viscose rayon is especially susceptible to shrinkage when washed and dried in home machines. The untreated fibers also stretch unevenly when wet, often causing a stretched-out, uneven appearance. Dry cleaning is the safest way to clean items made from this type of rayon.
High Wet Modulus rayon, or HWM, is manufactured in much the same way as standard rayon, but is specially treated to withstand normal home washing and drying without damage, stretching or shrinkage. HWM rayon is often wrapped in cotton, giving it a silk-like finish and extra strength. This type of rayon, also known as polynosic or modal rayon, is most often used in clothing due to its silky finish, soft drape and simple care needs.
Cupromonium rayon looks and feels much like standard rayon but is manufactured using nearly three times the water and energy as any other type of rayon. Due to its large environmental footprint, U.S. manufacturers refuse to produce it in favor of cheaper, "greener" rayons. However, it is still widely produced throughout the world, and is often found in inexpensive imported home décor products. This type of rayon should only be dry cleaned, as it is produced with no protective treatment and has a lot of shrinkage when washed or dried.
HT rayon, or high-tenacity rayon, is most often used in automotive or industrial applications. It is manufactured with at least twice as many fibers per square inch as standard rayon and is specially treated with coatings for extra strength. This type of rayon, because of its uses, will rarely need to be cleaned. However, should the need arise, it should only be dry cleaned, and never dried in a clothes dryer.