The G&S Design™ Commercial Grade 10 Cup Bundform Pan is made of heavy gauge, aluminum clad steel. This is the same durable construction that is used in pans in professional bakeries. The aluminum clad baking surface conducts and distributes heat evenly for professional results every time. The surface is extremely durable and will not rust or corrode. Over time, the pan will darken slightly with use to enhance its overall performance. Seasoning the pan before or between uses is not required.