I was referring to acrylic gel mediums like the ones you see here:
http://www.dickblick.com/products/liquitex-gel-mediums/ These are Liquitex brand, but Golden makes great ones too, and there are other brands as well. At the Dick Blick site you can see definitions of gel mediums and the effects, like glossy, textured, matte, different mediums produce. If you find the mixture too thick when you mix them with mica powder, you can add water to thin the liquid. Powdered and liquid gum arabic work also. But it's easier to find gel mediums and Mod Podge on sale.