Credit to: http://westwood.fortunecity.com/ghost/818/craftshomedecor.htm
Add more or less water to get the desired texture and thickness.
Add 2 Tbsp. varnish, for shine.
1/4 c. non-self rising flour
1/2 tsp. powdered alum
1 3/4 c. water
1/4 tsp. oil of cinnamon
Gradually add 1 cup water, stirring vigorously to break up lumps.
Boil until clear and smooth, stirring constantly. Remove from heat.
Add remaining water and oil. Stir until thoroughly mixed. Put into container with screw on lid.