Tamlyn offers several different finishes for its aluminum reveal trims. Clear Anodized (Architectural 200R1). The Clear Anodized siding options finish is an electrochemical conversion process that deposits an oxide film on the aluminum trim. A natural oxidation process occurs on bare aluminum, however producing the oxidation process artificially creates a thicker, harder, and more durable “oxide film”. Clear Anodized exterior siding is an extremely durable finish and is resistant to most forms of corrosion. Please Note: Clear Anodized Finishes can vary from one piece of trim to another. This is one of the characteristics of the anodizing process and must be considered before any orders are placed.