Shaving cream, glue, and food coloring (optional...Sarah said when they did this at the hospital they left it white). I'm not sure of the exact ratio of shaving cream to glue. In all honesty I put some shaving cream into the container and then added a bunch of glue, there was no measuring on my part during this process.
I split ours into 4 different containers and had this:
I then let Brianna loose to paint on paper plates. Obviously you can use paper, but we always have an abundance of paper plates around here and always end up short on paper thanks to my little artist.
After all was said and done it was a little messy, but easy to clean up and Brianna had a blast, although she was less than thrilled with how dirty her hands were.
We had a great time and finger painting is good for those of us a little over the age of 3 as well :) Thanks again Sarah for sharing the great idea!!