I know that I’ve been using “80 grams” paper, but I didn’t really understand why it was called “80 grams” until today.
What does gsm mean?
GSM is an abbreviation for grammage, or grams per square metre. It indicates the weight of a square metre of paper. Standard copy paper in Singapore is approximately 80 gsm, which means that a standard A4 sheet weighs 5 grams, and a 500 sheet ream weighs 2.5 kg.
Is gsm the same as thickness?
Not exactly. Thickness is measured in microns (millionths of a metre, or thousandths of
a millimetre). Standard copy paper typically has a thickness of about 100 microns, so
a 500 sheet ream is about 5cm thick. If two sheets have the same density, then their
thicknesses will be directly proportional to their grammage.