What you needChildren's bubble bath
First you will need to have the kids put on their water aprons.
Take some paint and add a small amount of water and place into a bowl. Add the bubble bath and froth up the paint and water till the paint is bubbling.
Now have the children place a piece of paper over the bubbles to create a bubbly print onto the paper. Keep frothing up the bubbles by blowing into the paint with a straw.
Aprons that are disposable can be bought from plastic bag suppliers or hairdresser supplies.