I take my skins cover with water bring to a simmer for about 15 minutes and then allow to sit overnight. Next day I bring to a simmer and let simmer for about an hour before adding my fabrics, fibers, etc. I allow the fibers to simmer for an hour, shut off the heat and allow the dyebath and fabric to sit overnight. This has yeilded me the best color to date that has been quite lightfast.