With this simplified batik technique, kids can turn a plain T-shirt into a summery top that will brighten up even a rainy day.
Cut the cardboard to fit inside the T-shirt (this will keep the fabric paint from bleeding through later). Mix the flour with water (it should be the consistency of mustard) in the measuring cup right before you're going to apply it so it doesn't have a chance to become gluey and difficult to use. Pour the mixture into the squeeze bottle and then use it to draw a sun pattern on the T-shirt. Let it bake in the hot sun for a couple of hours until hardened.
Spray the shirt with the fabric paint (we used Tulip brand) and let it dry in the sun.
Remove the cardboard, then have your child peel off the flour paste to reveal her summery design. Wash the T-shirt according to the paint manufacturer's directions.