📄 Paper Weight & GSM Guide
Convert between gsm and US pound weights across bond, text, and cover, and look up common papers with their use-cases and how well they take fountain-pen ink.
📄 Weight conversion
90 gsm is closest to Premium copy / writing paper (90 gsm / 24 lb bond) — fountain-pen friendliness: Good.
| Paper | gsm | US label | Fountain pen | Notes |
|---|---|---|---|---|
| Copy / printer paper Everyday office printing and photocopying. | 75 | 20 lb bond | Poor | Thin and lightly sized — fountain-pen ink often feathers, ghosts, and can bleed through. |
| Premium copy / writing paper Letters, resumes, and double-sided printing. | 90 | 24 lb bond | Good | Noticeably better — minimal feathering and little bleed with most inks. |
| Fountain-pen journal paper Journaling and everyday fountain-pen writing. | 90 | 24 lb bond (Rhodia / Clairefontaine) | Excellent | Tightly sized and smooth — crisp lines, vivid shading, and almost no bleed or feather. |
| Heavy writing / stationery Fine correspondence, certificates, and letterhead. | 120 | 32 lb bond | Excellent | Substantial and opaque — no show-through even with wet, broad nibs. |
| Cardstock / cover Cards, business cards, covers, and invitations. | 216 | 80 lb cover | Fair | No bleed thanks to the thickness, but coated stocks can be slow to dry and smear. |
US pound weights are measured on a different sheet size for each grade, so the same “20 lb” means different things across bond, text, and cover — gsm is the unambiguous metric. Fountain-pen friendliness depends on sizing and surface as much as weight.
Making sense of paper weights
The metric gsm figure — grams per square metre — is the honest measure of how heavy a sheet is. The US pound system is more confusing, because the “basis weight” is measured at a different sheet size for bond, text, and cover, so identical pound numbers can mean very different papers.
For writing, weight is only half the story. What matters most for fountain pens is how the paper is sized and surfaced: a tightly sized 90 gsm writing paper handles wet ink beautifully, while a loosely sized sheet of the same weight can feather and bleed. Use the table to match a paper to the job — and to your pen.
❓ Frequently Asked Questions
How do I convert gsm to pounds?
It depends on the paper grade, because US pound weights are measured on a different sheet size for each. For bond/writing/copy paper, gsm = pounds × 3.7607; for text/book paper the factor is 1.4805; and for cover/cardstock it is 2.7048. So 20 lb bond ≈ 75 gsm, 24 lb bond ≈ 90 gsm, and 80 lb cover ≈ 216 gsm.
What gsm is normal printer paper?
Everyday copy or printer paper is about 75 gsm, which is 20 lb bond. Premium copy and writing paper is around 90 gsm (24 lb bond), heavier stationery is 100–120 gsm, and cardstock ranges from roughly 176 gsm (65 lb cover) upward.
What paper is best for fountain pens?
Fountain-pen friendliness is about sizing and surface, not just weight. Cheap 75 gsm copy paper often feathers, ghosts, and bleeds, while well-sized 90 gsm+ writing papers such as Rhodia and Clairefontaine keep lines crisp and show ink shading. Heavier stock also reduces show-through with wet, broad nibs.
Why does the same pound weight feel different?
Because each paper grade uses a different basis-sheet size, a 20 lb bond and a 50 lb text are nearly the same physical sheet, while an 80 lb cover is much heavier than an 80 lb text. That's exactly why gsm exists — it measures the actual grams per square metre with no grade to decode.