First make a batch of the base:
1 tbsp. flour
1 tbsp. salt
1 tsp. baking powder
2 tbsp. water
I then separated the base into small cups and we added food coloring. The children each created some swirly artwork on cardboard painting with Q tips. Keep your paint thick and gloopy. Once you are done creating, dry it in the microwave for about 30 seconds and the paint puffs up.
This is really neat and a fun rainy day activity, though we painted outside since it is less clean up.