GSM (grams per square metre)

A measure of paper/board weight. Higher GSM means thicker, sturdier stock — relevant for bag strength and board rigidity.

GSM — grams per square metre — is the standard weight measure for paper and board: the mass of a single square metre of the stock. It's a proxy for thickness and sturdiness, so a higher GSM generally means a stronger, more rigid material.

In practice it tells you what a product can handle. Lightweight papers (low GSM) suit wraps, liners and greaseproof sheets; mid-weight stock suits carry bags; heavy GSM board makes rigid boxes, trays and sturdy cups. Matching GSM to the job avoids both flimsy failures and paying for more material than you need.

When comparing two look-alike products, GSM is one of the clearest spec-sheet numbers to check — a cheaper bag at a lower GSM may simply be thinner and weaker. Read it alongside dimensions and any coating to judge whether two lines are genuinely like-for-like.