- What does "print booklet PDF" mean?
- When you print a booklet on a standard printer, the pages must be in a special order — not 1, 2, 3, 4 but paired and rearranged so that when the sheets are stacked and folded, the reading order comes out right. This process is called imposition. For a saddle-stitch booklet (fold and staple), page 1 pairs with the last page on the same sheet, page 2 pairs with the second-to-last, and so on. This tool does all that rearranging automatically and produces a PDF you can print directly.
- Why must the page count be a multiple of 4?
- Each physical sheet of paper in a saddle-stitch booklet holds 4 pages: front-left, front-right, back-left, and back-right. A 12-page booklet therefore needs exactly 3 sheets, a 16-page booklet needs 4 sheets, and so on. If your PDF has, say, 10 pages, this tool automatically adds 2 blank pages at the end to reach 12, so the sheets come out even. You can trim those blank pages from the finished booklet or leave them for notes.
- How do I print the booklet correctly from my PDF viewer?
- Open the downloaded booklet PDF in your PDF viewer (Adobe Acrobat, Preview, or any browser). In the print dialog:
1. Enable duplex / double-sided printing.
2. Set the flip axis to "Flip on short edge" (sometimes called "short-side binding" or "tumble").
3. Set scale to 100% — do not "fit to page" or the crop marks and page sizes will shift.
Once printed, stack all sheets in order, fold the whole stack in half at the centre, and staple 2–3 times through the fold line.
- What paper size should I choose?
- Choose the paper size you will physically print on. The tool creates a landscape PDF at that size, and each source page fills half the sheet:
• Tabloid / 11×17 in → US Letter (8.5×11 in) pages after folding — most common for US home and office printers that support 11×17.
• A3 → A4 pages after folding — standard in Europe and most of the world.
• A4 landscape → A5 pages after folding — useful for smaller zines or if your printer only does A4.
- What is the gutter (binding margin) for?
- The gutter adds extra space at the spine edge of each page. Without it, text near the centre of the open book can disappear into the fold. A 6 mm gutter works well for booklets up to about 32–40 pages. Use 10–15 mm for thicker booklets where the bulk of the paper pushes the pages inward. If your PDF already has generous margins, you can set gutter to 0.
- What is the difference between Booklet (2-up), Side-by-Side (2-up), and 4-up?
- Booklet (2-up) reorders pages using saddle-stitch imposition so the output is ready to print, fold, and staple. Side-by-Side (2-up) keeps pages in reading order (1|2, 3|4, 5|6…) on each sheet — useful for review handouts or side-by-side comparison prints. 4-up places four pages in a 2×2 grid per sheet (1|2 top, 3|4 bottom) — useful for compact handouts or wallet-sized cards.
- Is my PDF uploaded anywhere? Is it safe to use with confidential documents?
- No. This tool runs entirely in your browser using the open-source pdf-lib library. Your PDF is read from your local disk into browser memory, processed there, and the result is written back to your disk. No data ever leaves your computer. It is safe to use with confidential, legal, medical, or commercially sensitive documents.
- Is there a page-count limit?
- There is no hard limit in the tool itself. PDFs with up to a few hundred pages typically process in a few seconds on a modern computer. Very large PDFs with high-resolution images may take longer and use more browser memory. If a very large file stalls, try splitting it with the Auto Split tool first, then imposing each section separately.