I guess if an asteroid is has high albedo already, a dark paint would be better for this purpose then dark. What you want is to make sure that some parts reflec

I guess if an asteroid is has high albedo already, a dark paint would be better for this purpose then dark. What you want is to make sure that some parts reflect much more light than other parts. However, I don't think you need vanta-black for this. You hit diminishing returns on a thing like this; so something like common soot would do just fine. Most asteroids are rather dark, though.