Oil Canning is a natural phenomenon that occurs in lighter gauge cold rolled metal. It gives the appeance of wavienss and in some cases can look as though the metal panels or the metal itself is defective, however oil canning is very common and is not a cause for rejection. Oil canning can occur in all types of metal; steel, aluminum, copper, stainless steel & zinc. There are a variety of ways to help reduce the oil canning look, see links below to get more information on oil canning to better help your purchasing decision.