Know your paper terms: What is GSM

If you’ve even casually glanced at a paper catalogue, you’ve almost certainly seen the paper products listed by GSM.  

For most purposes, GSM can be very easily explained: all you really need to know is that GSM effectively denotes paper thickness. The lower the GSM, the thinner the paper; the higher the GSM, the thicker.

Paper weight

GSM stands for grams per square meter. It is a measure of what is technically known as the grammage of paper. As the name indicates, that is a measure of weight. 

A higher GSM paper will be heavier duty (think food packaging) while a lower GSM paper will be lightweight and comparatively flimsy (think of a newspaper, which may be made of paper as low as 35gsm). 

But bear in mind, as the name implies, ‘grams per square meter’ is not strictly a measure of thickness. Though it is generally a reliable guide to how thick a product is, in the case of certain speciality papers, a paper may be more or less thick than the GSM would seem to imply. 

For that reason, it’s always a good idea to discuss your next project with an experienced paper professional, especially if you are likely to be using specialty papers or boards.