gsm stands for grams per square metre, it’s basically a measure of how heavy paper or card is. To make things complicated, gsm is only a loose guide for how thick a card is, because some treatments can make card heavy compared to its thickness. For example, gloss coating adds weight rather than thickness and very smoothed papers get squashed by rollers to smooth them out in the manufacturing process, making them more dense.
To try and keep things simple, we break gsm down into 6 categories.
Paper 80-120gsm
80gsm is your standard printer paper, which is flimsy and quite see-through and 120gsm is a much thicker, premium paper like you’d use for nice stationery.
Thick paper 130-190gsm
This is the weight you might use for a poster, it’s a bit thicker and hard wearing and less likely to tear.
Thin card 200-240gsm
We’re starting to see a little bit of structure, but if you need the card to stand up on its own, we would usually recommend a thicker card or layering.
Normal card 250-300gsm
The most common weight range for card, most home printers will have no problem printing on this thickness (always test) and it has a little bit of substance in your hands. As long as your card isn’t too big, it’ll be able to stand up on its own.
Heavy card 300-400gsm
This weight range is where the card starts to feel luxurious and substantial. Most home printers are going to start struggling with this weight.
Ultra heavy card 400gsm+
Thick and harder to bend. Cards at 400gsm and above are often ideal for letterpress and embossing. We use the thickest cards for book binding or protecting paper when it goes in the post.