What Does GSM Mean?
When shopping for paper, you'll almost always encounter a number followed by "gsm" — for example, 80gsm or 300gsm. GSM stands for grams per square metre, and it's the universal measurement used to describe how heavy (and therefore how thick and sturdy) a sheet of paper is.
The higher the GSM number, the heavier and thicker the paper. Simple as that. But knowing which weight suits your needs is where things get interesting.
Common Paper Weight Ranges Explained
| GSM Range | Paper Type | Typical Use |
|---|---|---|
| 35–55 gsm | Lightweight / Thin | Newspapers, Bible paper, airmail stationery |
| 60–90 gsm | Standard office/copy paper | Everyday printing, photocopying, writing |
| 90–120 gsm | Presentation / Quality paper | Letterheads, flyers, quality correspondence |
| 120–170 gsm | Light card / Thick paper | Brochures, booklet covers, menus |
| 170–350 gsm | Card stock | Business cards, greeting cards, postcards |
| 350+ gsm | Heavy card / Board | Packaging, covers, premium invitations |
Why Does GSM Matter?
Choosing the wrong GSM can cause real problems. Paper that's too light will bleed through when printed on both sides, feel flimsy for professional correspondence, or jam in your printer. Paper that's too heavy for your printer's specification can cause feed errors or poor toner adhesion.
- For home and office printing: Stick to 80gsm for everyday tasks. It's cost-effective, widely compatible, and performs well in most printers.
- For presentations and reports: 100–120gsm gives a noticeably premium feel without being too heavy for most desktop printers.
- For business cards and invitations: 300–350gsm card stock is the industry standard — it feels substantial and professional.
- For crafts and art projects: Weight depends on your medium. Watercolour artists typically use 300gsm+ to prevent buckling.
US Paper Weights vs. GSM
In the United States, paper is often measured using a lb (pound) basis weight system, which can be confusing because the same pound number can mean different things depending on the paper category (bond, text, cover, etc.).
As a rough guide:
- 20 lb bond ≈ 75 gsm (standard US copy paper)
- 24 lb bond ≈ 90 gsm
- 60 lb text ≈ 90 gsm
- 80 lb cover ≈ 216 gsm
- 100 lb cover ≈ 270 gsm
The GSM system is simpler and used internationally, which is why it's increasingly common even in North America.
Paper Finishes: The Other Half of the Story
Weight alone doesn't tell the full story. The finish of the paper dramatically affects how it looks and feels:
- Uncoated: Natural feel, absorbs ink well. Best for writing and everyday printing.
- Gloss coated: Shiny surface, vivid colour reproduction. Ideal for photos and marketing materials.
- Silk/Satin coated: A middle ground — smooth but not overly shiny. Popular for brochures and flyers.
- Matt coated: Non-reflective, elegant appearance. Preferred for high-end print work.
Quick Tips for Choosing the Right Paper
- Always check your printer's maximum paper weight specification before buying heavy stocks.
- When in doubt, request samples from suppliers before committing to a bulk order.
- Consider both weight and finish together — a 90gsm gloss sheet feels very different to a 90gsm uncoated sheet.
- For double-sided printing, go for at least 90gsm to minimise show-through.
Understanding GSM is one of the most practical skills you can have when buying paper. Once it clicks, you'll find it much easier to match the right paper to every task.