Sandwash is a process that buffs the fibers on the silk causing them to have a soft or worn texture. Unless the fabric has been coated with a chemical (which is unlikely) you should have no problem dyeing the silk.
silk hand painting process (2007-9-24 2:45:33)
China Silk Curture (2007-9-21 22:28:11)
◎welcome to give out your point。