This may be in the very wrong place, but it certainly can't hurt to ask. I have a pair of champagne flutes that I was hoping to decorate with henna. Since glass isn't porous, the henna won't leave a stain, so I was going to just let the paste dry and leave it on. I do the same thing with candles; to keep the paste from coming off the candle, I use Mod Podge glue sealant. However, I can't use Mod Podge on glasses. When I wash them the glue and the henna will come off. So. What sealants are there that are food-safe for use on glass, dry clear, and won't wash off?