Yeast, baking powder or baking soda is added as an agent that produces air bubbles to make dough or batter rise in cakes, breads or biscuits.

Cake, bread slices, foil, vegetables, wax paper or oil is placed in a pan or bowl to provide structure or to provide a dish from sticking when it is cooked. Potato slices make a good lining at the bottom of the pot to prevent rice dishes from sticking when it's heated.