Anodization changes the aluminum substrate at the molecular level. It is an electrochemical process where aluminum is treated to develop an exceptionally durable finish. Anodizing aluminum creates a surface that is three times harder than standard aluminum. Anodized tags will not chip, peel, or flake and have an extremely long life span. Because the anodization process is controlled oxidation of the aluminum, the product will never rust, develop patina, or weather. Increased wear resistance means a longer life cycle. The anodized surface is very hard, preserving and extending the life of the aluminum valve tags.