Mix the cornstarch and baking soda in a saucepan.
Turn heat to medium.
Stir for 5 minutes until thick.
Remove from heat.
Put on a sheet of waxed paper and knead for 5 minutes (when cool enough).
Form into flowers, animals, etc or cut with cookie cutters
Takes 48 hrs to 1 week to dry.
Paint with acrylic or tempra paint (acrylic coats better, but doesn't wash out of clothes).