Graham Crackers

1 cup shortening
2 cups brown sugar
1 cup white sugar
2 cups flour
4 cups graham flour
1 tablespoon baking soda
2 teaspoons baking powder
1/2 teaspoon salt
1 cup sour milk (mix 1 tablespoon vinegar and milk to make 1 cup, let stand for 5 minutes)
1 tablespoon vanilla

Cream shortening and sugar until fluffy.
Add vanilla.
Sift all dry ingredients twice.
Add sifted ingredients alternately with milk to shortening mixture.
Mix thoroughly after each addition.
Chill dough in refrigerator overnight.
In the morning, turn out on floured board, and roll as thin as possible.
Cut in squares or any shape desired.
Place on greased cookie sheet.
Bake at 350 degrees until crisp and golden brown.