Aluminium foil (or aluminum foil in North America), often referred to with the misnomer tin foil, is aluminium prepared in thin metal leaves with a thickness less than 0. 2 mm (7. 9 mils); thinner gauges down to 6 micrometres (0. 24 mils) are also commonly used. In the United States, foils are commonly gauged in thousandths of an inch or mils. Standard household foil is typically 0. 016 mm (0. 63 mils) thick, and heavy duty household foil is typically 0. 024 mm (0. 94 mils). The foil is pliable, and can be readily bent or wrapped around objects. Thin foils are fragile and are sometimes laminated to other materials such as plastics or paper to make them more useful. Aluminium foil supplanted tin foil in the mid 20th century.