It is used in chemical plants, water towers, etc. A one mil thick coating is all you need to protect the bare metal from corrosion. Then you can cover it with anything, oil base, latex, etc. It usually comes with a cool green tint which is transparent, and you can still see the metal surface finish through it. Your local distributor should also be able to get you some without the tint, which is of course clear.
Automotive lacquers used on metal objects create an intense illusion of depth.
It does require a good deal of time and it is quite thoroughly toxic and should only be performed with very adequate ventilation and a respirator suited to the purpose. Despite the required dedication of time and the need to check out and implement precautions, the results can be quite beautiful. Then apply a top coat. Sherwin Williams Commercial division has a graphite black premix that looks pretty good. It isn't as good as applying graphite dust while the paint is tacky, but repair touch ups are hard to match.