Definition: The weight, measured in pounds, of 500 sheets (a ream) of paper cut to a standard size is its basis weight.
That standard size (basic size) is not the same for all paper grades. The major paper grades such as bond or cover have their own standard sizes which determine the basis weight for that grade of paper regardless of the final size of the paper.
Pronunciation: [BEY-sis weyt]
Also Known As: basic weight | substance
Common Misspellings: basis wieght
Examples:
Bond paper, such as used in laser printers and copy machines, typically has a basis weight of 13-25 lbs. That weight is based on 500 sheets in a basic size of 17" x 22" although the paper is generally sold in 8½" x 11" sheets. Papers for many offset printing projects range in basis weight from 22-150 lbs.