There are many different ways to measure the "weight" of papers. The paper industry has used several different standards depending upon the specific application of the product. There are three commonly used measures for basis weight:

pounds per 1300 square feet (1300 square feet = 500 sheets of C-size
(17x22) paper)
pounds per 3300 square feet (3300 square feet = 10 reams of 500 sheets
A-size (8.5x11) paper)
grams per square meter (g/m(superscript: 2) or gsm)

Method 2 is commonly used for commodity ream papers. Methods 1 and 3 are commonly used for higher value-added products, such as inkjet photo papers. In the past, most U.S. companies, including Kodak, used method 1. As we have migrated to the metric system over the past couple of years, we have been moving to method 3. The industry as a whole is moving to method 3, the current ISO standard, to avoid the ambiguity of methods 1 and 2.

See more paper weight info inside...