Simply put; that's the weight of the fabric. But first, it's important to know that GSM also has some other acronyms that do mean the same; let's start with those. GSM (also known as gm/2) = grams per square meter and is the metric measurement of the weight of a fabric.
Keeping this in consideration, how thick is 250gsm card?
The Thickness of Printing Paper List
|250gsm signle side coated board||0.32|
|300gsm signle side coated board||0.425|
|350gsm signle side coated board||0.46|
|400gsm signle side coated board||0.54|
What is GSM for cotton?
GSM is short for grams per square meter. All fabrics have a weight, and the standard measurement for the weight and quality of fabrics (including towels) is grams per square meter. This number refers to the density of the towel. High quality Turkish cotton towels are generally heavier and are more absorbent.