Paper Weight Conversion GSM to LBS
Know about the paper weight and thickness conversion can help you determine the weight of a paper sheet of any size, gram weight and basis weight.
What does paper weight mean
Paper weight is also called “gram weight”. Paper weight refers to the mass per square meter of paper or cardboard, expressed in g/㎡.
In Hong Kong and Taiwan, it is called “basis weight”, which is commonly expressed in GSM.
GSM is an international common symbol, that is: how many grams per square meter of paper (by paper grammage tester).
The United States and the United Kingdom adopt the imperial system, and use pounds (Lb) to measure paper weight. That is, how many pounds or kilograms per ream of paper is expressed (the paper weight tester is not used when the quantity is large).
For example, the US book size is 25×38 inches. A standard of book paper with a basis weight of 60 pounds is 500 sheets of paper cut into a size of 31×43 inches and weighs 60 pounds, which is equivalent to 42.7 pounds of 35*38 inches US size.
70lbs text = 106.6gsm
70lbs cover = 189356gsm
Paper weight and paper thickness
Usually when we talk about the thickness of the paper, it is expressed in grams, but when printing and binding, we need to know the thickness of the page to calculate the thickness of the spine reserved for the cover. Even the same weight, different types of paper, the thickness is different. Usually, in the same GSM, the uncoated paper is thicker than coated paper.
Below listed 5 types of paper weight and paper thickness. Just for reference, different brand and supplier of paper, the thickness will have a bit of difference.
1 inch =25.4mm
Matte art paper
Coated one side paper