One of my clients marveled recently how beautiful my black is. She said it looked like rich calligrapher's ink.
So I'll let all of you in on my secret, which really isn't much of a secret at all. I find the black ink straight out of the can to be kind of flat and almost never use black straight out of the can. I add reflex blue, and quite a bit of it at that, to give it more body and to make it a richer jet black color.