Thanks to this blog I found via others, we decided to try out the recipe they provided for bathtub puffy paint. Let me just say, it was a little more work than anticipated (possibly because I was tripping over said peanut ever other minute :) When making for little ones, I would suggest doing some of the prep while they are asleep or otherwise occupied.
You need a cup of grated soap, 3/4 cup of hot water, and 1/2 teaspoon of dye according to the recipe posted. I used a few soap samples and bars we have brought home from hotel rooms in the past. We had to improvise a bit on the dye part- all I had was food coloring and I was afraid that would never wash off of my old porcelain tub! We have some Crayola washable finger paint that we substituted and it worked fine. The colors weren't nearly as vibrant and there wasn't a plethora of color options, but Emma didn't mind.
After wrestling with the cheese grater and soap, I realized I had a hand grater stored in the depths of my cupboard just waiting for a test drive. It worked so much better and wasn't nearly as messy. I'll admit this project was hard for me- I like everything neat and orderly (which can be my downfall sometimes). While grating the soap I couldn't control the flakes flying every where in my kitchen!
Once you have your soap grated, put it in a food processor or blender and slowly add the hot water. In the end, I thought the consistency was too thick and added more then the recommended water. I ended up adding a tad bit too much, but it still worked just fine. I then added paint to the mixture to give it some color.
Emma loved helping out with this part :) The original creator put her puffy paint in frosting tubes... I didn't have any and thought about using Ziploc baggies with the ends cut off, but decided that might be too much for little hands to control. We tried using medicine syringes, but that was a lot of work to keep reloading. In the end we used our hands.
She had a blast mixing colors and squishing it around! We went through half of our supply in a matter of minutes. I decided to package some of it up to use again in the future (someone has an aversion to baths lately and I figured this would be good motive for next time :)