Here is a recipe for a stiff buttercream frosting that is good for decorating. Note: there's no butter.

2 cups of shortening2 pounds of powdered sugar2 teaspoons vanilla extract4 to 6 tablespoons water2 tablespoons meringue powderPinch of saltCream the shortening, flavoring and water. Gradually add the other ingredients and blend on medium speed until creamy. This icing can be thinned by adding water (a teaspoon at a time) for easier spreading.