Units of paper quantity was ordered by the ream of 480 sheets. In 1840, a ream in Lisbon was 17 quires and 3 sheets = 428 sheets, and a double ream was 18 quires and 2 sheets = 434 sheets; and in Bremen, blotting or packing paper was sold in reams of 300 (20 quires of 15 sheets). A mid-19th century Milanese-Italian dictionary has an example for a "risma" (ream) as being either 450 or 480 sheets. In the UK in 1914, paper was sold using the following reams: Reams of 500 sheets were mostly used only for newsprint. Since the late 20th century,
Paper size the sheet of paper is folded in half widthwise, let "c" be the length of the new short side: "c" = . If we take the ratio of the newly folded paper we have: formula_3 Therefore, the aspect ratio is preserved for the new dimensions of the folded paper. Weights are easy to calculate as well: a standard A4 sheet made from 80 g/m paper weighs 5 g (as it is of an A0 page, measuring 1 m), allowing one to easily compute the weight—and associated postage rate—by counting the number of sheets used. The advantages of basing a paper