You may have heard of 100 lb gloss book, 80 lb gloss cover, 20 lb bond and other types of paper, but what exactly does this weight refer to?

Paper is measured in pounds per 500 sheets.  The paper manufacturer will select a standard sheet size for their paper when getting the initial weight on 500 sheets (this standard size varies brand-to-brand and can be 17” x 22”, 35” x 23”, etc.).  The weight of these 500 sheets determines the paper’s weight.

For example, the most commonly used office paper is known as “20 lb bond” has a standard sheet size of 17” x 22.″ This is the size that is weighed for 500 sheets. If 500 sheets of this size weigh 20 lbs then the paper is classified as a “20 lb bond.”

Some of other weights for bond paper are: 16 lb, 24 lb, 28 lb & 32 lb.  These would be thicker and thinner variations of the initial 20 lb bond.

So if you are carrying 4 reams of your standard letter-size (8-1/2″ x 11″) office paper, you are in fact carrying 20 lbs of paper, since 8-1/2″ x 11″ is a quarter of a 17″ x 22″ sheet.