Bookbinder'S Paste - cooking recipe

Ingredients

1 tsp. flour
2 tsp. cornstarch
1/4 tsp. alum (powdered)
1/3 c. water

Preparation

Mix dry ingredients.
Add water slowly, stirring out lumps. Cook in double boiler over low heat, stirring constantly.
Remove from heat when paste begins to thicken.
It thickens as it cools. Keep covered.
Thin with hot water when necessary.