Epsom salt frosted glass (washable, even) Dissolve 4 heaping T. Epsom salts in 1 cup of beer. This will foam. Let set for 35 minutes. Using a terrycloth washcloth dipped in mixture, dab over stencil designs. Wonderful for all season decorating, add 1 or 2 drops of food coloring if desired. Mixture dries to form beautiful crystals. Washes off easily with Water. Crystals look best after 24 hours.