Paper weight and GSM
GSM is grams per square metre. It is the quickest way to talk about sheet weight without mixing up thickness, stiffness, and opacity.
- 80-100 GSM: office and letterhead use
- 150-170 GSM: flyers and inserts
- 250-350 GSM: cards, covers and packaging inserts
Practical rule
If the job needs to feel premium in-hand, pick the heaviest stock that still folds, binds, or feeds correctly on the machine.