Paper ream

From Encyclopedia Jr, free information reference for Kids

A Ream of paper is a quantity of sheets. Formerly it was 480 sheets, 20 quires, for common sizes such as letter-size paper (8-1/2" x 11"). A printer's ream was 516 sheets, perhaps to allow for wastage. As part of international standardization, this quantity was changed to 500 sheets. The old value of 480 sheets is now known as a short ream.

In the United States, paper is typically described by a weight in pounds, with 20 pound and 24 pound as common weights. This measurement refers to the weight of 500 sheets of 17" x 22" paper of that type, which the manufacturer could cut into four letter-size reams. Thus, one ream of 20 pound letter-size paper weighs five pounds.

The metric unit for paper thickness, or grammage, is grams per square metre. Since 1 pound is 453.59237 grams, 1 inch is 25.4 mm, and 1 standard ream is 500 sheets of 17" x 22", a paper thickness of 20 pounds per ream corresponds to 75 g/m². See also the section expressing paper thickness and density in the article on paper size.

[edit] External links

• ream at A Dictionary of Units of Measurment
• ream at The Online Quantinary™, yet see quire at the same site for historical evidence of 500-sheet reams as early as 1590.