Which paper weight is best for fountain pens and markers?

Heavier paper resists bleed-through and ghosting. Listings in this pool range from 100 GSM (common on budget dot-grid journals like CAGIE and RETTACY) up to 160 GSM on the B5 bullet-dotted notebook, which verified-purchase reviewers most often cite as the friendliest here for wetter inks. As a general rule, look for 100 GSM or higher if you use fountain pens or brush markers.