Online Tool Store
PDF Booklet Maker
Impose a PDF two-up for saddle-stitch printing — shows sheet order, adds a spine-only gutter and fold line, and names every blank page. Runs in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Extra space at the spine edge of each page, for content that runs close to it. Never taken from the outer edge.
Multiples of four. Smaller signatures fold more cleanly on thick paper.
A thin guide line at the centrefold — helps you fold accurately, especially on plain paper with no visible crease.
Sheet order
What lands on each side of each sheet. Print double-sided, flip on the short edge, then fold the stack.
| Sheet | Side | Left | Right |
|---|
Print double-sided, flipping on the short edge. Long-edge flipping turns every second side upside down, which is the most common way a booklet comes out wrong. This also does not compensate for creep — on a thick booklet the inner sheets stick out slightly further and their margins should be shifted inward. For a handful of sheets it does not matter; for a thick one, a print shop's imposition software does it properly. Nothing is uploaded.
How to use it
- Drop in the PDF and pick a sheet size — two source pages fit side by side on each.
- Add a gutter if content runs close to the fold — it only takes space from the spine side, never the outer edge.
- Check the sheet order table, keep or turn off the fold line, then save.
- Print double-sided, flipping on the short edge, then fold the whole stack.
Why the page order looks backwards
Fold a stack of sheets in half and the outermost sheet becomes both the front and back cover — so it has to carry the last page and the first page on the same side. Working inward from there gives the pairing:
an 8-page booklet, 2 sheets sheet 1 front 8 | 1 sheet 1 back 2 | 7 sheet 2 front 6 | 3 sheet 2 back 4 | 5 folded, this reads 1,2,3,4,5,6,7,8
The two pointers start at the outside and step inward two at a time, which is short enough to write from memory and easy to get subtly wrong. This implementation was checked by simulating the fold at 4, 8, 12 and 16 pages and confirming the assembled booklet reads back as 1 to N in every case — a bad imposition still produces a plausible-looking PDF, so testing it against the physical result is the only way to be sure. Short edge, not long edge: this is the single most common failure and it is not the tool's fault. Duplex printing can flip the paper along either axis — a long-edge flip is correct for portrait documents but turns every second side upside down in a booklet, while a short-edge flip is what a landscape booklet needs. Because the sheets here are landscape, the reverse side has to be flipped about the short edge for the backs to line up with the fronts. Most printer dialogues call this "flip on short edge" or "short-edge binding". If your first attempt comes out with alternating upside-down pages, this is why. Multiples of four, and where the blanks go: one folded sheet yields four pages, so the page count must be a multiple of four. There is no way around it, and it is not a limitation of the software but of paper. A 13-page document becomes 16 with three blanks; a 6-page one becomes 8 with two. Where those blanks land is determined by the imposition rather than chosen, and the sheet order table names every blank explicitly. That matters if your last page is meant to be a back cover — you may want to reorder the source so the blanks fall somewhere you are happy with rather than immediately before it. Signatures, for anything thick: a single folded stack works up to roughly 40 to 60 pages. Past that the fold bulges, the innermost pages stick out badly, and stapling through the spine stops being practical. Signatures split the document into smaller folded groups — typically 8, 16 or 32 pages — which are then collected and bound together. That is how any book you own is made. What this tool does not do is compensate for creep. In a thick folded group, the inner sheets protrude further than the outer ones, so trimming the edge leaves their margins narrower — real imposition software shifts each sheet's content progressively inward to correct it. For a few sheets the effect is invisible. For a thick booklet, that shift is exactly the sort of thing a print shop's software exists to handle, and it is worth using it.
FAQ
What is saddle-stitch imposition?
Rearranging pages so that when the sheets are printed double-sided, stacked and folded down the middle, the pages read in order. Sheet one carries the last page and the first page on its front, because those two end up facing outwards once the stack is folded.
Why does my printed booklet come out with upside-down pages?
Almost always because the printer flipped on the long edge instead of the short edge. Long-edge duplex rotates every second side, which is correct for ordinary portrait documents and wrong for landscape sheets folded into a booklet. Set the duplex option to flip on the short edge and print again.
Why do I get blank pages at the end?
Because a folded sheet always makes four pages, so the total has to be a multiple of four. A 6-page document becomes 8 with two blanks, a 13-page one becomes 16 with three. The blanks are placed where the imposition puts them, which is typically the inside back — the tool shows exactly where before you save.
What is the difference between saddle stitch and signatures?
Saddle stitch folds the entire document as one stack, which is fine up to roughly 40 to 60 pages depending on paper thickness. Beyond that the fold gets ugly and the creep becomes severe, so the document is split into signatures — smaller folded groups, sewn or glued together. Choosing 16 pages per signature is a common compromise.
What is creep, and does this handle it?
On a thick folded stack, the inner sheets protrude slightly further than the outer ones, so after trimming their margins are narrower. Proper imposition software shifts each sheet's content inward to compensate. This tool does not do that, and says so — for a few sheets it is invisible, and for a thick booklet you want a print shop.
Is my PDF uploaded?
No. The file is read, imposed and saved entirely in your browser. Each source page is embedded once and drawn where needed, so the output does not balloon in size.
Where exactly does the gutter space come from?
From the spine edge of each page only. Half the gutter is reserved on each side of the fold, and the outer, trimmed edge of the sheet keeps its full width — a gutter is there to stop text disappearing into the binding, not to shrink the whole page.
Do I need a printer that supports double-sided (duplex) printing?
Yes — the imposition puts different content on the front and back of each sheet, and those two sides need to land back-to-back for the booklet to fold correctly. Without a duplex printer, print all the odd output pages first, reload the stack the right way round, then print the even pages on the reverse — running one test sheet first is worth it before committing the whole job.
Is this the same as a digital flipbook maker?
No. This produces a print-ready PDF with pages reordered for saddle-stitch imposition — something you fold and staple. If you want an online page-flip viewer for reading a document on screen rather than printing it, that is a different category of tool.
How we compare
| Feature | Online Tool Store | Printer driver booklet mode | Imposition software |
|---|---|---|---|
| Produces a PDF you can inspect before printing | ✓ | ✗ | ✓ |
| Shows the sheet order and every blank | ✓ | ✗ | ✓ |
| Works on any printer, since output is just a PDF | ✓ | Driver dependent | ✓ |
| Signatures for thicker documents | ✓ | ✗ | ✓ |
| File never leaves your device | ✓ | ✓ | ✓ |
| Creep compensation | ✗ | ✗ | ✓ |
| Fold-line guide printed on the sheet | ✓ | ✗ | ✓ |
| Gutter taken only from the spine, never the trim edge | ✓ | No gutter control | ✓ |
| Full crop marks, bleed and colour bars | ✗ | ✗ | ✓ |
Better than a printer's booklet mode because you get a PDF you can check first, it tells you where the blanks fall, and it draws a fold line so a plain sheet still folds accurately. It has no creep compensation or full bleed and colour-bar support — for a commercially printed job, those are the reasons imposition software exists.