I got the idea from Little Wonders. She uses it with her crew frequently. Here she gives great step by step directions on how to do it. Unfortunately I did not have these directions while we were actually doing the project. Without the directions, I missed a step. We did not squeegee our bags. I am not sure what kind of difference that will make.
Here is our bag collection drying. I think the colors would be more vivid if we had sqeegeed. It was so much fun though. I am sure we will do it again for other occasions.