Aluminum foil is made from high-purity aluminum (typically 99%+ purity, sometimes with added strengthening elements) that is hot-rolled into thick sheets and then cold-rolled to a thickness of 0.006–0.2 mm. It is highly flexible and serves as an excellent barrier against moisture, oxygen, light, and bacteria; it offers good thermal conductivity and high reflectivity for both light and heat. Due to the rolling process, it features one glossy side and one matte side. It is widely used in households for food storage and cooking, as well as in industrial applications for packaging, thermal insulation, and electronic shielding.