Homemade play dough

1 cup flour
1/2 cup salt
2 tbsp cooking oil
1 cup water
2 tsp cream of tartar (this is the key ingredient!)
few drops of food coloring

Mix ingredients in saucepan and cook until thick. Drop on waxed paper and knead. Store in covered container and it will keep for weeks.

variations: add sparkles, mix colors, etc.