From top of my head:
- UniBall Eye / Vision Elite's Red, Blue and Black (look for fade-proof / water-poof note, or SuperINK)
- Sakura / Faber Castell / Rotring pigment inked, felt tip markers (Look for Archival Ink / Fade Resistant)
If you prefer fountain pens: - Pelikan 4001 blue black (which is not sold in the US)
- Rohrer & Klinger's Iron Gall inks (scribosa, ebony, etc.)
- Noodler's "Bulletproof" series cellulose reactive inks.
- Lamy Blue Black
- Lamy Crystal Benitonite
- Montblanc Permanent Blue / Permanent Black
I'm sure there are many more, but these are the ones I know and had experience with.Always use an acid-free higher quality paper. Leuchtturm 1917, Rhodia, Yu-Sari, Mnemosyne comes to my mind. Do NOT use Moleskine notebooks with fountain pens. They are not designed for fountain pens.
Or for hard use in general. Well over priced for the quality of the paper and bindings.
They gradually reduced their quality, and created a “higher, more expensive tier” to offer their previous quality.
Leuchtturm 1917 is a world apart when compared to today’s Moleskine.
Or, for gel-based, the Uniball Signo black ink is my second choice. I particularly like using the Signo GelStick 0.7mm which I can make line variations from hairlines to super broad strokes (again, the leverage-based force application is key for effortless pressure variation techniques)