I've read so many many times that Old Manhattan is rated to be the blackest black. And in all scans, it looks quite dark, although it's hard to judge the darkness by the scans only. But my own Old Manhattan Black looks to be much paler than I have expected. OK, it's a true black without any red or brownish tint, but it's more grey than a true velvety black. Heart of Darkness and even Private Reserve Ultra Black both look much much darker. Old Manhattan looks like Aurora Black to me, very black at the start, but after some pages, it fades to a dark grey. Is it just that I possibly have gotten a wrong bottle? Or just because I've just opened the bottle and so the effect of shaking it isn't that strong? Don't get me wrong, it's not a bad ink, but just I've expected Old Manhattan Black to be the ultimate black ink and it turns out pretty ordinary in my pens. Worse.

I use OMB, and I get a dark, consistently black line, but viseguy just compared four Noodler's blacks in an unscientific papertowel test and found that OMB shows green whereas HoD is just black. See the photos here.

Again, not scientific, but interesting nevertheless.

I have the PR Ultra Black, and for me, it's a problem ink. Much too fast and feathery.

I still stand by OMB, but I'm ordering the HoD... for my own comparison. (The Aurora, while very black and pleasing, was also too wet for my speed.)