Paper Stock & GSM Explained: A Plain-English Guide

Every print quote mentions GSM, silk, gloss or uncoated — and most explanations assume you already know what they mean. This guide explains paper stock in plain English, so you can choose the right paper for business cards, leaflets, booklets and stationery with confidence.

GSM Is Weight, Not Thickness

GSM stands for grams per square metre — it measures how much a square metre of the paper weighs. Physical thickness is a different measurement called caliper, measured in microns (µm). Two papers of the same GSM can feel slightly different because denser pulp adds weight faster than bulk. In practice, GSM is your reliable guide to how substantial a stock will feel:

GSM Feels like Typical uses
80–100gsm Everyday office paper Letterheads, compliment slips
115–170gsm Quality flyer/poster paper Leaflets, posters, booklet inners
250–300gsm Light card Covers, greetings cards, budget business cards
350gsm Standard card Business cards, bookmarks, tags — the professional default
450gsm Rigid premium card Premium business cards, strut card faces

As a rough conversion, 350gsm silk card is about 0.35mm thick.

Silk vs Gloss vs Uncoated

Coated papers (silk and gloss) have a fine mineral coating that keeps ink sitting near the surface — printers call this good "ink holdout". The result is sharper detail and more saturated colour. Gloss is shiny and makes colours pop; silk is smooth with a soft low sheen — the modern professional default; uncoated has no coating, so ink soaks into the fibres. That absorption mutes colours slightly and softens fine detail (a printing effect called dot gain), but gives a natural, tactile finish — and crucially, uncoated is the only surface you can reliably write on with everyday pens.

Quick Decision Guide

  • Vivid colour and photos → gloss or silk
  • Professional, glare-free look → silk
  • Writeable (compliment slips, appointment cards) or natural/eco feel → uncoated
  • Premium touch → 450gsm with matt or velvet lamination (lamination needs stock above ~250gsm, or the card curls, and can't be applied to uncoated)

Where This Applies in Our Range

Business cards (350/450gsm silk or uncoated), folded leaflets and booklets (115–170gsm inners, heavier covers), compliment slips (100–120gsm uncoated), bookmarks and gift tags (350gsm-class card). Not sure? Message us and we'll recommend the right stock for the job. Browse the full business stationery & publications range.

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