Carbon steel
Traditionally, frying pans were made of cast iron, carbon steel or copper lined with tin, for their different qualities and properties. Copper pans are highly thermally conductive, making them useful for evenly sautéing. However, they are also highly reactive with most foods, so today a large number of copper pans are sold with a tin lining which can be replaced when it wears out. Cast iron pans are used because although they do not conduct heat very evenly, they do retain it quite well, making them useful for searing meats and vegetables. Carbon steel cookware is used because over time it can develop a highly nonstick patina of polymerized oil called seasoning useful for cooking protein that is prone to stick, such as fish and eggs. While all of these materials are still commonly used in professional kitchens, many modern materials have supplanted them in the consumer market. Nowadays, most frying pans are now made from metals such as aluminium or stainless steel. The materials and construction method used in modern frying pans vary greatly and some typical materials include: