What is foil?

   FOIL is a very thin sheet of metal, 0/1000 inch thick or less. Although lead, tin, copper, and other metals can be rolled to foil, aluminum is generally used because of its lightness and low cost. A pound of aluminum foil thick will cover 29,200 square inches. Because of its high impermeability to moisture, oil, and grease, aluminum foil is used for containers and closures for food, drugs, and beverages. Electrical and electronic devices utilize its great electrical conductivity. Foil's reflectivity to heat makes it excellent for insulation. Foil is also used in household cooking, preserving, and freezing of foods.