Black Anodizing
Black anodizing is a process through which the surface of an anodized metal is dyed black. Before the sealing stage of anodizing, the oxide surface of a metal can be dyed. This is done when the exterior appearance of the product is significant. There are countless dye colors to choose from, including black anodizing.
Because black dyes are made by inorganic means, dyes used in black anodizing tend to be more lightfast. The occurrence of lightfastness means that the colors tend to fade.
Once a metal has been dyed, hot water or steam, often mixed with nickel acetate, is used to seal the surface and to convert the oxide into its hydrated form. This process decreases the potential of bleeding and can improve corrosion resistance.