I posted a caution about RIT on the AAW site as well. It isn't all that permanent if exposed to sunlight. This from my wife's direct experience with her hats. She uses two of the more professional dyes instead (also a bit more expensive) and doesn't have this problem. Any can be used with alcohol vs. water and then covered with a finish, but unless you're certain the piece won't be exposed to a lot of light (including fluorescent), you might want to use something better than RIT.