I’ve had good experiences with Rohrer & Klingner Salix. It’s an iron gall ink so it’s permanent. It’s somewhat dry (as most IG inks) but that also means that it will work fairly well on cheap paper.
There’s of course also the various nano pigment inks, especially the ones from Sailor come to mind. But I’ve not used those myself. Rohrer & Klingner has the SketchINK line which are also nano pigment inks. I think there’s a blue one in there as well.