rohrer & klingner salix
Since I first discovered that there were inks apart from black Quink, blue Quink and red biro, I have been fond of blue black inks, despite the problem of them rarely actually being blue or black. For instance, Waterman Blue Black, which is one of the most used, dries to be a distinct turquoise, which is sort of vaguely blueish I suppose but has no connection to the name at all. (Quink Blue Black is apparently identical to it nowadays, incidentally, due to companies being consolidated - I certainly can't see any difference.)
I first tried Rohrer & Klingner inks when I saw that they had an purple iron-gall ink called Scabiosa, which is rather an unpleasant name for a nice ink that behaves much like J Herbin Poussière de Lune but with more shading and permanence. I don't hear an awful lot about R&K inks on the net, but the three that I've tried so far seem to be good performers - all fairly dry so you do need a fairly wet pen.
Anyway, Salix. As you can see from the pictures in this post I tested it first with a Lamy 2000 with a broad nib, which was loaded with Lamy Blue Black when the Salix arrived. It behaves very much like Lamy BB - I've read that it is "drier" but I can't see that myself. It flows well and consistently.
As an iron gall ink, just like Lamy BB, it doesn't feather or bleed even on this relatively cheap paper, and shades significantly. Drying time is good and fast, there is no smearing and it is extremely waterproof. (Soaking the paper in water and swooshing it around a bit just resulted in the paper tearing rather than the ink.)
The major difference between it and the Lamy BB is that it's noticeably more blue, though not really blue in comparison to blue inks. (Lamy BB simply is not blue when it dries, I'm sorry. At least it's not turquoise.) I prefer either dark or muted blues, myself, so that's fine for me, but if you're looking for an iron gall Waterman Blue this is not it. It's quite similar to Pelikan Blue Black in colour; it reminded me a bit of J Herbin Bleu Nuit, a little greyer.
I then tried it with a glass dip pen, and the results were much less distinct. The dip pen tends to produce a quite thick line of ink, and when thick layers of iron gall ink dry, they go a dark black regardless of what other colours are present, so the comparison is not that useful, but I made it anyway. I also threw in some Pelikan BB and some Diamine Registrar's Ink too.
So far I'm fond of this ink - respectable colour but with enough shading to stop it being boring, more vibrant on the page than the Lamy BB (which does get a bit dull to look at after a while) and with all the handy qualities of other iron gall inks, waterproofness, no feathering etc. I think I'll keep it in the 2000 B for a while, or at least until I get some my next bottle of ink.