Best Paper Weight Guide: GSM vs LB Explained
GSM (grams per square meter) is a direct, comparable measure of paper thickness — higher always means heavier. The US "lb" system measures something else entirely: the weight of a ream of the paper's uncut parent sheet size, which changes by category, so 24 lb bond (90 gsm) and 24 lb cover don't weigh the same at all. For most printables: 20–24 lb (75–90 gsm) for everyday pages, 32 lb (120 gsm) for planners that get handled daily, and 65–110 lb cardstock (176–300 gsm) for certificates and anything meant to stand up on its own.
Last updated: August 24, 2026
GSM vs LB: two different measuring systems
GSM is straightforward: it's the mass in grams of one square meter of the paper, full stop. A 200 gsm sheet is always twice as heavy and thick as a 100 gsm sheet, regardless of what kind of paper either one is. It's the standard used almost everywhere outside the US.
The US "lb" (pound) system instead measures the weight of 500 sheets (a ream) at that paper type's traditional uncut "basic size" — and the basic size is different for each paper category. Bond and writing paper use a 17 × 22 in basic sheet; cover and cardstock use a 20 × 26 in basic sheet, which is roughly 1.5× larger in area. That's why 24 lb bond paper (90 gsm) is thinner than 65 lb cover cardstock (176 gsm) even though 65 sounds like "not that much more than 24" — the two numbers aren't on the same scale at all. Always check whether a "lb" rating is bond/text weight or cover/cardstock weight before comparing two products.
Quick conversion table
These are the weights you'll actually see on paper packaging, with their approximate GSM equivalents:
- 20 lb bond ≈ 75 gsm — standard copy/printer paper, the default in most home printers.
- 24 lb bond ≈ 90 gsm — a step up from standard, noticeably less see-through, common for resumes and reports.
- 32 lb bond ≈ 120 gsm — premium presentation weight, still flexible enough to fold and bind.
- 65 lb cover ≈ 176 gsm — light cardstock; bends but holds a crease, common for postcards and index cards.
- 80 lb cover ≈ 216 gsm — mid-weight cardstock; the usual choice for greeting cards and certificates.
- 110 lb cover ≈ 300 gsm — heavy cardstock; rigid, near business-card thickness, holds a shape without support.
These are approximations because GSM-to-lb conversion also depends on the paper's specific fiber blend and finish, but they're accurate enough to shop by within a few percent.
What to use for each type of printable
Everyday printing (graph paper, lined paper, habit trackers you'll replace monthly). Standard 20 lb (75 gsm) copy paper is fine. There's no durability need, and heavier stock just slows down high-volume printer trays and costs more per page.
Planners and daily-use pages (to-do lists, weekly planners, dot grid you'll write on constantly). Step up to 24–32 lb (90–120 gsm). These pages get folded, carried, erased, and handled far more than a one-time printout, and the extra body resists show-through from pen ink and reduces curling from humidity.
Certificates and awards. 65–80 lb cardstock (176–216 gsm) is the standard for anything meant to be handed to someone and kept. It has enough rigidity to feel substantial without being so thick it jams a home printer, and it resists the slight cupping that happens when thin paper absorbs ink from a full-bleed colored border.
Anything with a photo background (photo calendars). Use inkjet photo paper or heavyweight matte photo paper rather than judging by lb/gsm alone — photo paper's coating (glossy, matte, or luster) affects how ink sits on the surface far more than raw weight does. If sticking to plain paper, go with at least 32 lb (120 gsm) so ink saturation from a full-color background doesn't cause the sheet to warp or curl as it dries.
Handwriting practice paper for kids. Standard 20 lb is fine — the priority is a smooth, non-textured surface pencils and crayons glide on, not thickness.
Inkjet vs laser: weight limits differ
Most home inkjet printers handle up to 24–32 lb (90–120 gsm) through the standard paper tray without complaint, and many can push cardstock up to 65–80 lb (176–216 gsm) through a rear or manual-feed slot designed to keep the paper path straighter for stiffer sheets. Check your printer's manual for its specific manual-feed maximum before trying anything above 80 lb — forcing 110 lb cardstock through a standard tray is one of the most common causes of a jam that's hard to clear.
Laser printers use heat to fuse toner, so very heavy or coated stock (thick cardstock, glossy photo paper) can risk melting, curling, or jamming near the fuser roller — check for a "cardstock" or "heavy paper" mode, which usually slows the print speed and increases fuser temperature dwell time to compensate. When in doubt, print one test sheet of a new paper weight before running a full batch of certificates.
Is higher GSM always better?
Not for every use — heavier paper costs more, takes longer to print, and can jam printers that aren't rated for it. Match the weight to how the page will be used: thin and cheap for disposable everyday printing, heavier only where durability or a "premium" feel actually matters.
Why does 65 lb cardstock feel so much thicker than 24 lb bond, even though 65 sounds like less than double 24?
Because they're measured on different basic sheet sizes (see "GSM vs LB" above) — the lb numbers for cover/cardstock and bond/text paper aren't directly comparable. In GSM, 65 lb cover (176 gsm) actually is close to double 24 lb bond (90 gsm), which matches how much thicker it feels.
Can I use regular copy paper for a certificate?
Yes, it'll print fine — but 20 lb copy paper feels noticeably flimsy for something meant to be framed or kept, and it's more prone to visible curl once ink dries on a full-color border. Cardstock (65–80 lb) is worth the small extra cost for anything given as an award.