Which plating is the best for glossy-black finishing? black chrome?

Q. I'm an optical engineer. I'm making a light absorber so called 'light trap', which is shaped as a cone. Its desirable function is a total extinction of incident light to the light trap. To do this, the inner surface of the cone should be a form of mirror-like surface with low optical reflectivity.

Would you recommend a proper plating method? From googling, I found that a black chrome plating might be a good candidate, but I'm not sure whether it provides a glossy surface and whether it provides a quite black color not gray.

June 2, 2012

A. What metals are you planning to use? Have considered pure titanium? If yes, black matte on titanium is very color absorbing, although we have not conducted any experiments.

Anna Berkovich Russamer Lab Pittsburgh, Pennsylvania