How the layouts are checked
- The folds: each fold scheme is folded in a simulator, one fold at a time, as a folding machine would. The pages are then read off the folded section and must come out in order, every head up, with the spine on the binding edge. The same check runs in the app, in the Signatures table and the folding dummy.
- The page maps: saddle-stitched and perfect-bound books of many lengths, with blanks, nested and gathered sections, against page orders worked out by hand (on a 16-page saddle-stitched sheet, the pages on each side add up to 17).
- The PDF itself: real PDFs are imposed and the output read back with an independent tool (Poppler's pdftotext), finding every page's number on every sheet and checking where it is and which way up.
- Marks: every crop, fold, registration and collating mark is checked to sit clear of the trim and bleed and on the sheet.
- The gang optimiser: compared with a brute-force search of every way of sharing the slots, on 400 random cases: it finds the fewest sheets every time.
The automated checks
| Suite | What it checks | Checks |
|---|---|---|
| Fold | Every fold scheme read back 1 to n, heads up, spine on the binding edge | 37 |
| Signatures | Planning books into sections, saddle and perfect page maps, blanks, creep | 20 |
| Layout | Pages on press sheets, gripper and margins, work styles, gaps, n-up, cut and stack | 36 |
| Marks | Marks clear of trim and bleed, on the sheet | 201 |
| Gang | Slot sharing, against brute force | 11 |
| Imposing real PDFs and reading every page back from the output | 172 | |
| Preflight | The findings on a deliberately awkward PDF | 15 |
| Job | The whole job model end to end, including double-sided n-up | 16 |
| Total | 508 |
The figures in the ten how-to guides on this site were read from the app's own results, and each guide's video was recorded by a script driving the real app in a browser.
What the output keeps
Pages are placed as vectors (PDF Form XObjects), not rasterised, so text, lines, spot colours and overprint go to the RIP exactly as the designer made them. Each page is clipped to its bleed box, so a page's bleed never prints over its neighbour. Creep and nudges move the page inside its clip.
What has not been checked yet
- Plates and printed sheets: the output is checked by reading it back, not yet by making plates on a press and folding the result. Always run a proof before plating.
- Comparison with Quite Imposing, Fiery Impose or Kodak Preps output on the same real jobs.
- Very large PDFs (hundreds of megabytes): they work, but imposing them in the browser is slower than on a prepress server.
- Covers with a spine, bottling, generating bleed and batch imposing are not built yet.
If you print for a living and something lands in the wrong place, tell us: we will add your job (with your permission) to the checks.