Paper Weight and Calliper: Choosing Stock by Function

Paper shopping is confusing on purpose. A pack says "65 lb", another says "176 gsm", a third says "216 gsm" and feels thinner than the first. None of the numbers are lying — they are measuring different things in different systems. For a journal maker, the useful question is not "what does the pack say" but "what job will this sheet do". This guide separates the numbers and maps them to function. ## Three properties, often confused * **Basis weight** — how much a defined area (or a defined ream, depending on the system) weighs. In the US, "lb" is basis weight and depends on the paper type: 28 lb text and 28 lb cover are not the same sheet. In most of the world, **gsm** (grams per square metre) is absolute and comparable across types. * **Calliper** — thickness, usually in mils (thousandths of an inch) or millimetres. Two papers of the same weight can differ in thickness because of density and bulk. * **Stiffness** — how much the sheet resists bending. This is what a pocket or cover actually needs, and it depends on thickness, fibre and coating — not weight alone. A dense, heavily coated 120 gsm sheet can feel floppier than a bulky uncoated 120 gsm sheet. That is why two papers labelled the same weight behave differently in the hand. ## Approximate map of common stocks Use this as a starting point, then test the actual paper you bought. Conversions between lb and gsm are approximate and vary by paper type. | Stock | Approx. gsm | Behaviour | Best use in a journal | | :--- | :--- | :--- | :--- | | 20 lb copy | ~75 | Thin, translucent, weak folds | Practice sheets, templates, scrap paper | | 24 lb text | ~90 | Light, decent print surface | Inserts, lightweight pages, ephemera to cut | | 28–32 lb text / presentation | ~105–120 | Good body, folds cleanly, low show-through | Journal pages, signature spreads | | 65 lb cover / cardstock | ~176 | Firm, holds a crease, printable in most inkjets | Pockets, tags, covers, envelopes | | 80 lb cover | ~216 | Substantial, crisp folds, nearing printer limits | Structured pockets, covers, folios | | 100 lb cover | ~270 | Board-like, often needs a straight feed | Cover boards, heavy folios, boxes | If your printer's manual gives a maximum weight, respect it. Most consumer inkjets handle light cardstock comfortably; heavy cover stock may require the rear feed and one sheet at a time. A jammed sheet costs more in time than a lighter stock costs in feel. ## Choosing by job, not by number | Element | Priority | Target stock | | :--- | :--- | :--- | | Signature pages / spreads | Fold endurance, low show-through | 28–32 lb text, matte | | Pockets and tuck spots | Tear strength, stiffness | 65–80 lb cardstock | | Tags and labels | Crisp edges, light weight | 32 lb text or light cardstock | | Covers | Stiffness, abrasion resistance | 80–100 lb cardstock or laminated cover | | Overlays | Transparency, smoothness | Printable vellum or tracing paper | | Fussy cuts | Clean cutting, low bulk | 32 lb text, matte | > **Buy one pack, test five sheets:** Before committing to a ream, print a page, fold it, glue a pocket to it, and leave it under a book overnight. The paper that passes those tests is your paper — regardless of what the label promised. ## Weight and the spine budget Heavier paper makes a thicker book. A 32 lb page stack is noticeably thicker than a 24 lb stack with the same page count, and a 65 lb pocket adds more bulk than a paper one. If you are planning a journal to a fixed cover size, weigh the trade-off: heavier pages feel better and show less ink through, but they consume spine allowance. Our guide to [page count and spine budget](/blog/planning-junk-journal-page-count/) shows how to measure before cutting. ## Reading a paper label without being fooled * **"Text" vs "cover"** — in US labelling, these are different scales. 65 lb cover is much heavier than 65 lb text. * **"Cardstock"** is a marketing word, not a specification. Check gsm or calliper. * **"Premium"** tells you nothing measurable. Look for weight, finish and printer compatibility. * **Matte vs glossy** affects how the sheet takes ink, glue and distressing — more in [the coating guide](/blog/coated-vs-uncoated-paper/). Once you know what each number means, shopping becomes simple: choose the sheet for the job, test it in the size you will actually use, and keep a note of the exact product that worked. Paper is the most repeated purchase in this craft — a little specification discipline pays back on every build. --- *Next in the series: <a href="/blog/grain-direction-paper/">grain direction and why folds crack</a> · <a href="/blog/paper-strength-tear-fold/">paper strength: tear, tensile and fold endurance</a> · <a href="/blog/paper-weight-calliper/">paper weight and calliper</a>.*