Units of paper quantity size and type of paper being sold. Reams of 500 sheets (20 quires of 25 sheets) were known in England in c1594; in 1706 a ream was defined as 20 quires, either 24 or 25 sheets to the quire. In 18th- and 19th-century Europe, the size of the ream varied widely. In Lombardy a ream of music paper was 450 or 480 sheets; in Britain, Holland and Germany a ream of 480 sheets was common; in the Veneto it was more frequently 500. Some paper manufacturers counted 546 sheets (21 quires of 26 sheets). J.S. Bach's manuscript paper at Weimar
First Folio texts were beyond the typesetters' capacity to correct. The Folio was typeset and bound in "sixes" – 3 sheets of paper, taken together, were folded into a booklet-like quire or gathering of 6 leaves, 12 pages. Once printed, the "sixes" were assembled and bound together to make the book. The sheets were printed in 2-page formes, meaning that pages 1 and 12 of the first quire were printed simultaneously on one side of one sheet of paper (which became the "outer" side); then pages 2 and 11 were printed on the other side of the same sheet (the "inner" side).