Paper used in furniture design. Watercolor paper has a long history of production and use. The thickness of paper is often measured by caliper, which is typically given in thousandths of an inch in the United States and in micrometers (µm) in the rest of the world. Paper may be between thick. Paper is often characterized by weight. In the United States, the weight assigned to a paper is the weight of a ream, 500 sheets, of varying "basic sizes", before the paper is cut into the size it is sold to end customers. For example, a ream of 20 lb,
Units of paper quantity × 17" and smaller is packaged and sold as bundles of 25 pounds. A paper bale is a quantity of sheets of paper, currently standardized as 5,000 sheets. A bale consists of 5 bundles, 10 reams or 200 quires. As an old UK and US measure, it was previously equal to 4800 sheets. Units of paper quantity Various measures of paper quantity have been and are in use. Although there are no S.I. units such as quires and bales, there are ISO and DIN standards for the ream. Expressions used here include U.S. Customary units. A quire of paper is