[LeonidasXIV]

Keep in mind that R&K only has two iron gall inks: Sallix and Ebony. The rest is normal inks, but of good quality for sure.

KWZ got started as a producer of iron gall inks but has branched out a bit since. But they still have a large range of colors of IG inks, potentially the largest: https://mountainofink.com/blog/kwz-ink

I have some of them, the gold one is a lot of fun as it darkens as you're writing.

[MezzoDelCammin]

got Salix inked MB146 in my pocket right as I write this! It's a really nice ink for higher end pens (I probably wouldn't dare putting it into anything with a steel nib).

If the long-term properties / resistance of the ink are important, R&K also makes one of the few archive grade inks - their Dokumentus. A bit more expensive, but still affordable compared to alternatives. It's nice, but a bit higher maintenance than the Salix / IG inks. I think part of the permanence is achieved by some powder emulsion, so long term storage of an inked pen can be an issue (past maybe a month or so, or even a week in hot and dry weather).

[_giorgio_]

at least 3: black, salix, scabiosa