When we manufacture aluminum parts for customers, most people require kinds of anodizing: black hard anodizing, normal black anodizing, natural anodizing and other color anodizing, some even require multi-colors anodizing, like acid washing, splashing and fading…

Anodizing looks very beautiful, but not easy to ensure all the same. Even coming from the same batch, parts may look different with anodizing coating, not mention to different batches. Then what causes the color difference?

Firstly let’s see the principle of aluminum oxidation:

Immerse aluminum or aluminum alloy products into electrolyte solution, with the use of electrolysis, then the surface of products is covering with an alumina film.

Therefore, during the process, many things can affect it, like different chemical oxidation tanks, different grades of dyes, different sizes of products, different grades of materials, the depth of products immersing, immersing time etc