Preflight checks PDF files of any size and page count, with the limits below. They keep one very large file from holding up everyone else's reports.
Files#
- PDF only. An upload that isn't a PDF is refused ("Only PDF files are supported."). A file that reaches the check without being a PDF ends with "The file is not a PDF." A PDF uploaded on the Preflight page can be up to 200 MB.
- Checked on arrival in Files are PDFs of up to 250 MB, in drops or API batches of up to 200 files (see Running preflight). Larger files and drops can still be checked from the Preflight page.
- No password. A file that needs a password to open can't be checked. One that opens but is encrypted can: the Encryption check flags it and Remove encryption fixes it.
- Memory. A file that would need more memory than a report may use, usually because of a huge image, ends with "The file needs more memory to check than preflight allows (for example a huge image)."
Pages#
Every check runs on every page, except:
| What | Pages |
|---|---|
| Bleed and Total ink coverage | the first 30 |
| Finding a die from the file's cut lines | the first 30 |
| Page previews | the first 24 |
| Page sizes and boxes kept with the report (to place finding outlines) | the first 200 |
A finding keeps up to 25 locations; its count still includes every occurrence.
Time#
A report runs in the background. It is stopped when it runs for about 13 minutes, and ends as "The check took too long and was stopped." A report still running after 15 minutes, or not started within an hour of being queued, ends with an error too. Run it again; if a file keeps timing out, simplify it where it was made.
Precision#
- Ink coverage is measured at up to 150 dpi and averaged over 0.5 mm squares. Very large pages are measured at a lower resolution, so the whole page stays within the same number of pixels: a 1 × 3 m banner is measured at about 50 dpi. Coverage from a CMYK rendering, used when a page can't be separated, is an estimate (see total ink coverage).
- Bleed is sampled every 2 pt along the edge, at up to 72 dpi (lower on very large pages). Gaps that affect 3 % of the edge or less are not reported.
- Lightest tint checks flat colours only: tints inside images and gradients are not checked.
- Safety margin checks text only, not images or graphics near the edge.
Rates#
Each person can start up to 30 preflights and apply up to 10 fixes a minute, in the app and through the API
together. Past that, the app says "Too many preflights started in a short time. Wait a minute and try again." (or "Too
many fixes applied in a short time…" for fixes), and the API answers 429. The fixes have limits of their own, see
Preflight fixes.
Lists#
- The Preflight page lists the 50 most recent reports.
- The Run preflight dialog offers the 300 most recent approval versions and shows up to 60 that match the search.
Reports stay with their artwork#
A report is kept until its artwork version, imposition artwork or version in Files is deleted (a version in Files goes when it is deleted from its file or the file is deleted from the trash); its page previews go with it.