Silk fabric tends to shrink about 1-2cm after washing. If you want to make silk clothes out of a piece of silk fabric, your need to know how to pre-shrink silk fabrics.

Silk Fabric Shrinkage Rate 
Name & Shrinkage Rate
Silk Habotai 3-6%
Silk Organza 3-5%
Silk Georgette 13-15%
Silk Crepe de Chine 9-12%
Silk Heavy Crepe 9-13%
Silk Crinkle GGT 18-23%
Silk Crepe Satin 4-6%
Silk Twill 4-6%
Silk Taffeta 1-2%
The above is the shrinkage rate of silk fabrics after finishing with ordinary shrinking machine when the silk fabric has not been preshrunk.
If pre-shrinking is done according to the upper limit of shrinkage rate, the shrinkage rate of silk fabric after wash won’t exceed 2%.
If pre-shrinking is performed according to the upper limit of shrinkage rate, the shrinkage rate of silk fabric after wash won’t exceed 1%.
If pre-shrinking is done according to the upper limit of the shrinkage rate, the width of the fabric will also shrink accordingly. For example , silk georgette, after pre-shrinking according to the upper limit of the shrinkage rate, its width will be 105 cm (original width is 114 cm).

How to Prevent Silk Fabrics from Shrinking
1. Remove dust or colored miscellaneous threads from silk fabric.
2. Put some salt in cold water at a ratio of 0.2 grams per meter silk fabric
3. Gently soak the silk fabric for 10-15 minutes to preserve the color and          prevent the fabric from hardening.

4. It needs to be rinsed several times with clean water; gently rub it with your hands when washing, and do not twist it with force after washing to avoid wrinkles.
5. In order to keep the silk bright and soft, you can add a few drops of white vinegar during the final rinse.