I have not made it yet, but want to save it for future reference (cookie decorating for gingerbead men or sugar cookies). Source: Parents magazine. This is supposed to be a smooth, hard-drying icing that works well for making cookie decorations that last. It can also be used as a "cement" to fasten decorations together. (It is not recommended for icing cakes.)
Royal Icing Recipe
1 box (16 oz.) xxx sugar
2 TBS egg-white powder
6 TBS water
assorted icing colors
In large bowl, with mixer on low, beat xxx sugar, egg-white powder, and the water until well combined. Increase mixer speed to high, and continue beating for 5 minutes. Divide icing among 5 blows. Tint 4 of the bowls with various icing colors such as red, pink, yello and green. If icing is too thick, think out with a few drops of water before decorating cookies.
See also http://en.wikipedia.org/wiki/Royal_Icing.
