GSM is an acronym for “Grams Per Square Metre’ which means how much a single sheet of paper measuring 1m x 1m weighs. The lower the GSM the lighter the paper and the higher the GSM the heavier the paper. … 70gsm to 80gsm. This range of paper weight is commonly used as office paper and is normally used as copier paper. Heavier weight cartridge papers like the Snowdon Cartridge 300gsm can cope with stronger mark-making…