This icing is the type that you put on the cookie wet and it dries to decorate the cookie.  I had a friend who would decorate her entire Christmas Tree with painted cookies using this icing except she had to use egg whites.  The following recipe has been modernized with a new product called "Just Whites" that can be found in the baking aisle of the supermarket.  You will also need food coloring for the desired colors you want on your cookies.

In a large bowl beat 3-1/2 cups powdered sugar and 1/4 cup "Just Whites" on low speed.

Slowly add 1/3 cup water and beat until blended.

Increase speed to high and beat for about 8 minutes until icing is thick.

Makes 2-1/2 cups of icing.

Separate icing into bowls and use Wilton's Food Coloring Paste to get the colors needed for your cookies.

You will need to store the painted cookies in a cool place but not the refrigerator as the icing will stick to the next row of stored cookies from the condensation.