How to Impose a PDF for Saddle Stitch

Imposition maps logical reader pages onto physical sheets. In saddle-stitch 2-up work, each side of a sheet holds two reader pages, left and right of a fold. The outermost sheet carries the cover and the last page. Inner sheets nest. You fold the whole pile once. That is one signature.

This product does not do perfect bind, spiral, or multiple signatures. Perfect bind stacks folios at a spine glue edge; the page order is not this formula. If you need that bind, do not use these sheets.

Each sheet has four slots: front left, front right, back left, back right. A 5-page PDF cannot fill those slots without empty places. We never drop your pages. We append blank pages until N is a multiple of 4. A one-page PDF becomes four pages: your page plus three blanks. A five-page PDF becomes eight.

For N=8, sheet 0 (outer) is 8|1 on the front and 2|7 on the back. Sheet 1 (inner) is 6|3 then 4|5. Page 1 is the front cover because it sits front-right on the outer sheet. See the 8-page booklet page order worked example.

Four sheets. Outer: 16|1 and 2|15. Then 14|3 and 4|13. Then 12|5 and 6|11. Innermost: 10|7 and 8|9. Full table on the 16-page booklet imposition page. The same formula scales to 20, 24, and beyond.

You do not have to fill the table by hand. Open the PDF booklet maker, load the file, preview Sheets / Reader / Spreads, and export. Creep and gutter are optional. CropBox (else MediaBox) is the artwork. Bleed is a user inset, not a printer-mark scanner.