1 c. cornstarch
2 c. baking soda
1 1/4 c. cold water

Mix in a saucepan. Heat slowly, stirring constantly, until the mixture is the consistency of moist mashed potatoes. Pour out on a plate. Cover with a moist cloth. When cool enough to handle, knead like dough. Smooth the mixture out. The mixture can then be molded and shaped as desired.