# Paper weight (GSM / lb)

> Source: https://www.infinitelibrary.ai/glossary/paper-weight

Last updated: 2026-09-06
Category: Printing & binding
Also called: Paper stock · Basis weight · Caliper

Paper weight is stated in gsm or US pounds; book interiors are typically 50–60 lb (75–90 gsm) and covers 80–100 lb or 10–12 pt board.

## Definition

**Paper weight** is how paper stock is specified. The international measure is **gsm** (grams per square metre) — one number, comparable across all papers. The US system quotes **pounds** per ream of 500 sheets at a *basis size* that differs by paper category, which is why 80 lb *text* (118 gsm) is thin and 80 lb *cover* (216 gsm) is card: the two are weighed on different sheet sizes. Board for covers is often quoted by thickness instead, in **points** (thousandths of an inch): 10 pt is a standard paperback cover.

Book interiors are usually 50–60 lb text (about 74–90 gsm), in **white** or **cream**; cream is kinder to the eye for long fiction, white is used for anything with images. Colour books use heavier coated stock, 70–80 lb, for sharp images and less show-through.

Weight sets the **caliper**, and caliper × page count is the spine width — so paper choice changes the cover template.

## In Bindery

Bindery’s print presets pair each binding with the printer’s stocks — cream for black-and-white text, coated for colour — and the quote shows the per-copy price before payment.

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