Foiling is applying a pigment wet. You can use water, or fix plus, or mixing medium, or eyedrops... really whatever you want to use. I tend to use either water or setting spray. Really intensifies the look of the pigment. Note: this doesn't work well with matte pigments =] eta: I don't foil with the glitter glue. The glitter glue really intensifies the pigments without wetting them. eta (some more): the glitter glue is sticky. I find the best way to use it is to use a regular primer (if necessary), do ALL your crease work... apply your transition etc. Pat the GG over our lid, and then apply the glitter or pigment where you put the GG. It can be hard to blend over the GG so that's why I do it that way. Its easier to just blend the edge of your lid color than it is to try to blend your transition colors over the GG.