I really like to use silk as a dry fly dubbing so a while back I snapped up a lifetime supply of raw silk. I dye alot of furs and feathes for fly tying and I have alot of success with the standard acid dyes like veniards so I didn't see any problem. Raw silk sucks up acid dye like a sponge but the problem is that the dye molecules move out of the silk substrate as easily as they move in and no matter how long I soak in acetic acid to try and fix the dye, it will just keep leaching out as long as I continue to rinse the dyed silk. A bit of digging turns up the fact that silk is a fibroin protein which is somewhat different from the keratin proteins which make up animal furs and feathers. People have been successfully dying silk for at least 5 or 6 hundred years. It's hard for me to believe that I would need any really complex chemistry to do it at home.