I know that the glue added to the shaving cream is to stablize it and let it dry puffy, but I have found that it serves another purpose. The food coloring doesn't stain the fingers when you use the glue. I used this idea for a preschool class that I teach. I knew that they would be using their fingers, so I first tried with out the glue. After a few minutes, my fingers were stained. After adding the glue, the color came right off with washing. I even had one boy (5yrs) who totally coated his hands with the mixture, let it dry and then coated them agian. Even his hands came almost Totally clean. I'm glad I decided to try this suggestion, even though we weren't using the craft to let it dry as puffy paint. Thanks.
Katel