Paper weight

Paper weight is listed in either lbs (pounds) or GSM (grams per square meter). Keep in mind that the paper might feel a little bit thinner or less sturdy, depending on the finishes that were applied to the paper.

GSM

GSM indicates grams per square meter of paper. It's a straightforward way of knowing how heavy (and thus thick) the paper is. GSM is often written as g/m².

80 GSM is the standard printer paper you use at home or in the office.

300 GSM is most commonly used for business cards, postcards, or handmade cards. It's advised to use 250 GSM or 300 GSM paper for your card base.

Lbs

Lbs indicates the pounds per 500 larger sheets (before cutting them to size). The size of this sheet can differ between manufacturers or paper types, which means that the lbs indication on a pack of paper will not necessarily tell you how thick or sturdy it is. You can find online converters for lbs to gsm, but keep in mind that it won't give you a guarantee of the actual paper weight, since the lbs indication depends on the brand and manufacturer.