In the atmospheres found in nature, aluminum forms a thin layer of aluminum oxide which has protective properties. However, such untreated aluminum has a mechanically very soft surface susceptible to physical damage and also chemical corrosion. If aluminum strip is treated with sulfuric acid etc. in a continuous direct-current process on an "anodising line", it acquires a different kind of oxide surface layer which is hard rather than soft, and has much better physical and chemical resistance. The surface can be made to have desirable and uniform optical properties (either high reflectance or high optical absorptance, depending on the anodising process). The "anodized" strip can then be processed in any of a variety of metal forming processes without detriment to its optical properties.  

Anodized aluminum from ALANOD can be printed on, cut, straightened, roll-formed, profiled, bent, drawn, beveled, stamped, punched, and perforated.