The checks that catch most rejections
Print files fail for boring reasons far more often than exotic ones. A merged document with three page sizes. A flyer exported at the trim size with zero bleed. A headline in a font nobody embedded. A logo still in RGB. This tool reads both the PDF’s geometry and its page contents, and flags exactly those, in seconds, instead of the printer’s queue doing it overnight.
The rules come from a production preflight engine we built for a commercial printer, running against their real product profiles: digital, offset, large format, foil, and contour-cut work.
What it will not pretend to know
A preflight tool that cries wolf is worse than no preflight tool, and one that gives false comfort is worse still. So where the browser genuinely cannot know something, the report says so instead of inventing a verdict.
Image resolutionis the clearest case. Measuring true DPI needs each image’s placement size, which lives in the content stream we do not parse. What we can compute is the resolution an image would have placed at page size. Most images are placed smaller than that, and so print sharper — but one scaled past the page prints coarser, so the estimate is strong evidence rather than proof. The check only calls a file safe when it clears double the 300 DPI target, and otherwise reports the number and says plainly that it is an estimate.
Ink coverage needs an ICC colour engine, and PDF/X conformanceneeds a certified validator. Neither runs here. If your printer asks for a formal PDF/X report, use Acrobat Pro’s Preflight or veraPDF.
Fixing what it finds
| Finding | Fix |
|---|---|
| No bleed | Re-export at trim + bleed. The bleed calculator gives exact targets |
| No TrimBox | Enable printer’s marks / bleed settings in the export dialog |
| Mixed page sizes | Rebuild from one source at one size; check pages in the page size checker |
| Password protection | Re-save without security from any PDF viewer |
| Nonstandard size | Confirm against the product spec. Custom sizes are often intentional |
If the file needs rebuilding rather than re-exporting, the PDF to JSON converter opens it as an editable design where sizes and bleed can be set properly before a clean export.
