Silk DOES shrink.
More Info: Although most silk fabrics are hand washable, they can shrink when washed in warm water.
Why Does Silk Shrink?
Silk does not shrink for the same reason as other fabrics. Silk is a fiber very similar to human hair that comes from silkworms’ cocoons. Silkworms create a glue called sericin as part of the spinning process. This glue is only partially removed during the processing of silk. The glue that remains in the silk fabric is activated by hand washing and can naturally shrink the fabric.
How Much Does Silk Shrink?
The amount that silk fabric shrinks will vary based on how tightly woven the fabric is. If the fabric is woven loosely to begin with, as in lighter weight silks like crepe de chine, washing will tighten the weave and shrink the fabric. If the fabric is tightly woven to start with, hand washing in warm water should cause much less or no shrinkage. However, if the silk has not been washed before the garment was manufactured, it can shrink regardless of the fabric’s weave. This is why, if you sew at home, it is recommended that you preshrink your fabric by washing it.
What is the Best Way to Wash Silk?
Most silk fabrics can be hand washed in warm water with a gentle shampoo. Silks do tend to soften when washed, so if this is a concern for you, you may want to consider having your item dry cleaned. If hand washing, make sure not to wring out your silk fabric. Instead, roll it up in a towel to dry. You should avoid machine washing or machine drying silk.
” Silk Fabric Care and Sewing.” Denver Fabrics. N.p., n.d. Web. 19 Oct. 2012. http://www.denverfabrics.com/content/silk/silk-fabric-care-sewing.aspx
“Silk: This is the fabric that makes its own statement! Fabrics.net.” Fabrics.net « Hand Selected Fabrics, Timeless Elegance Fabrics.net. N.p., n.d. Web. 19 Oct. 2012. <http://info.fabrics.net/fabric-facts/silk/>.