GSM

GSM (grams per square metre) is the metric measure of paper weight: how many grams one square metre of the sheet weighs. It is an absolute number, so it means the same thing at any sheet size — unlike the US “lb” system, which depends on the paper’s base size.

Business cards are typically 300–400 GSM. Everyday cards sit around 250–310 GSM; premium cards use 360–400 GSM. Heavier is not automatically better — the finish and the design matter as much as the weight.