Royal Icing

This is the traditional recipe that glues gingerbread houses together or makes a hard candy-like surface on cookies or cakes.

Ingredients:

16 oz powdered sugar (icing sugar)
3 egg whites
1/2 tsp cream of tartar

Procedure:

Beat until peaks firmly hold their shape, and the more you beat it, the firmer it gets. This hardens when exposed to air, but dissolves in water, so keep a moist towel over the bowl while working with it. Use a tight-fitting plastic container to store in the refrigerator for a couple weeks, but the egg whites begin to separate from the sugar any longer than that.

Makes enough to ice 5-6 dozen sugar cookies.