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). The same was done with pages 3 and 10, and 4 and 9, on the second sheet, and pages 5 and 8, and 6 and 7, on the third. Then the first quire could be assembled with its pages in the correct order. The next quire was printed by the same method: pages 13 and 24 on one side of one sheet, etc. This meant that the text being printed had to be "cast off" – the compositors had to plan beforehand how much text would fit onto each page. If the compositors were setting type from manuscripts (perhaps messy, revised and corrected manuscripts), their calculations would frequently be off by greater or lesser amounts, resulting in the need to expand or compress. A line of verse could be printed as two; or verse could be printed as prose to save space, or lines and passages could even be omitted (a disturbing prospect for those who prize Shakespeare's works).