The size of a standard U.S. postage stamp changes slightly depending on whether it is printed in a booklet or a roll. The Four Flags Forever stamp, which came out in 2012 in a booklet of 20 and is 0.87 inches wide by 0.98 inches high, was printed on paper that is 0.87 inches thick.
The size of the stamp includes the border that goes around the edge. Some stamps that come on a roll are narrower than those that come in a booklet. The U.S. Postal Service has more than one printer that makes stamps. Each printer makes stamps that are a little bit different size. The size difference is usually less than a millimetre.
