CLAY: 1 box baking soda (about 2 cups), 1 cup cornstarch, 1 1/2 cups water & use of stovetop. Mix all the ingredients in small pan and cook over medium heat, stir consistently until too thick to stir. Cool for 10 minutes. Knead for 5 minutes or until smooth. Wrap dough in plastic wrap to save or mold into crafts, ornaments, etc. Once molded, it takes 1 to 3 days to dry and harden. Paint with tempura or acrylic paints.