Many Quo Vadis planners use 90 gsm Clairefontaine paper which is designed for fountain pen use. (See the list of fountain pen friendly Quo Vadis planners here.) The thick paper is super-smooth and gives a wonderful writing experience.
The paper is great will all kinds of pens, not just fountain pens. I know people who enjoy using their felt tips and Sharpie pens with no bleed through. Others use their gelly rolls and other colored pens and love how crisp the ink looks on the white paper with no feathering.
I’ve always held up the 90 gsm Clairefontaine paper as my gold standard of what writing paper should be. I don’t use fountain pens, but I enjoy using my roller ball pens and Sakura Microns on the smooth paper. I love the feel of the pages and the way my hand glides over the surface while writing.
Which pens do you use on the 90 gsm paper?