Homemade playdough

Here's a recipe for playdough you can make right at home:

2 cups water
2 1/2 cups flour
1/2 cup salt
1 1/4 tablespoon alum
3 tablespoons vegetable oil
food coloring

Add food coloring and oil to water. Stir in dry ingredients. Knead until smooth. Stores well in a refrigerator for several months.