There are several different recipes floating around the Internet, but the one that I chose to use was:
1/2 cup flour
2 tsp baking powder
2 tsp salt
enough water to form a smooth paste
I made a double batch and poured the paint into six containers. I then added some food coloring to each container.
We used paintbrushes to create our designs, but q-tips would also work, or you could put the paint in squeeze bottles. I cut up a cardboard box for us to paint on. Since the creations have to go in the microwave to puff up, regular paper won't work.
Trip and his friends had a fantastic time painting and I was so busy microwaving that I didn't get any pictures. Once they were done with their artwork, I would put it in the microwave. It took about 30-45 seconds on high for the paint to puff up and get dry. A couple of pieces took a little longer, but I always stopped every 15 or so seconds to check on it.
Trip enjoyed creating some abstract designs.
I made some flowers.
We discovered that you do need to put quite a bit of paint on the cardboard for it to really puff up. One of our friends had the idea to drip globs of paint from his paintbrush to make polka dots. He then started dripping colors on top of other colors and created some really cool designs.
They puffed up really nicely.
I think this might become a new go-to activity when we have friends visiting. I always have the ingredients on hand and the kids really enjoyed seeing their artwork come out of the microwave.