Book schemes
Book Imposition & Signatures Explained (with Diagrams)
Offset-printed books are printed on large sheets that are folded into signatures. These diagrams show where every page lands.
Signature schemes
Saddle-stitch booklet layouts
Signatures needed for common page counts
| Book length | 16-page signatures | 32-page signatures |
|---|---|---|
| 96 pages | 6 x 16 pp | 3 x 32 pp |
| 128 pages | 8 x 16 pp | 4 x 32 pp |
| 160 pages | 10 x 16 pp | 5 x 32 pp |
| 192 pages | 12 x 16 pp | 6 x 32 pp |
| 224 pages | 14 x 16 pp | 7 x 32 pp |
| 256 pages | 16 x 16 pp | 8 x 32 pp |
| 288 pages | 18 x 16 pp | 9 x 32 pp |
| 320 pages | 20 x 16 pp | 10 x 32 pp |
| 352 pages | 22 x 16 pp | 11 x 32 pp |
| 384 pages | 24 x 16 pp | 12 x 32 pp |
| 416 pages | 26 x 16 pp | 13 x 32 pp |
| 448 pages | 28 x 16 pp | 14 x 32 pp |
Offset page counts are planned in whole signatures; spare pages become blanks, ads or extra back matter.
Make a folding dummy
Before sending files to an offset printer, fold a blank sheet the same way the signature will be folded, number the pages, then unfold it: the numbers show the imposition. Printers handle imposition themselves, but a dummy helps you understand why page counts must be multiples of 4, 8, 16 or 32.