1 1/2 cups water + 2 Tbs. water
1/2 cup salt
1 tsp. food coloring

Mix the ingredients above and put in pan. Heat until it boils. Pour heated mixture over the following flour mixture:

Flour mixture: 2 1/4 cups flour and 2 Tbs. powdered alum (optional) in a mixing bowl.

After adding heated mixture, add 1 Tbs. salad oil. Stir all together in bowl as fast as you can. When you cannot stir anymore, put on board and knead until mixed well. The play dough does not need to be refrigerated. It may be stored in a wide-mouthed jar with a tight lid or in a sealed plastic bag.

found it on http://www.play-therapy.com/prof_playdough.html