Rayon is only washable if the garment label specifies.
More Info: Though some of today’s rayon garments are treated specifically to handle washing, many continue to be labeled ‘dry clean only’ and should never be washed in water.
Why Dry Clean Rayon
Rayon is a cellulose fiber that once dyed or treated with a special finish such as sizing, do not fully absorb the treatments. Subsequently, contact with water may cause dyes to bleed or may remove sizing treatments that can cause the garment to shrink extensively. Dry cleaning fluids do not cause the same reactions, but may not be able to remove water-soluble stains.
Can I Hand-wash Rayon?
Most rayon fabrics specify “dry-clean only” for washing options, but there are some that can be hand-washed or machine-washed on gentle as long as the care label is marked as such and you keep in mind that wet rayon is not as durable as when it is dry. If you are going to hand-wash use only mild detergents and lukewarm water. Never scrub or wring the garment. You can remove excess water by gently rolling the garment up in an absorbent towel. Lay rayon sweaters flat to dry. You can hang additional garments making sure not to use a wire hanger that could rust.
“Rayon: Caring for Your Fabric.” Sedgwick County Research and Extension Office. N.p., n.d. Web. 27 Oct. 2011. <http://www.sedgwick.ksu.edu>.
“Rayon Fiber – Rayon Staple Fiber, Rayon Textile Filament Fiber, Rayon Industrial Filament Fiber.” FiberSource: The Manufactured Fiber Industry. N.p., n.d. Web. 27 Oct. 2011. <http://www.fibersource.com/f-tutor/rayon.htm>.