The color of the Chromic Anodize coating varies from light gray to dark gray depending on the alloy. It is not as readily dyed as sulfuric anodize. The salt spray requirement is 336 hours using a 5% solution per method 811 of FED-STD-No. 151 or ASTM B117. The minimum weight for Type I coatings is 200 milligrams/sq. ft.
Chromic anodize is a thin coating that will scratch easily. Therefore, it can be used for inspection of aluminum forgings or castings by noting evidence of chronic acid bleed out from laps, cracks, seams, etc..