Print Ready Check

How the print check works

A plain description of what's measured, the thresholds used, and what isn't checked. No part of the check uses AI; the same file always gives the same result.

Where your file goes

Nowhere. The page loads the checking code into your browser, reads the PDF on your device, and shows the report. The file isn't uploaded, stored or logged.

Input and output

  • Input: one PDF file, up to 150 MB. Password-protected PDFs can't be checked; PDFs with only editing or printing restrictions can.
  • Output: an on-screen report of problems, warnings and passed checks, page previews with trim, bleed and safe-area lines, and, where it's safe, a corrected PDF.
  • Content checks (fonts, colors, images) cover the first 300 pages. Page previews, edge checks and text-position checks cover the first 20 pages.

The checks

Page size and trim

Reads the trim size stored in the PDF (the TrimBox). If there isn't one, the visible page (CropBox) is used. Sizes within about 0.7 mm of a standard size are named (US Letter, A4, business cards, postcards, posters and others). Pages whose sizes differ by more than 1 point (0.35 mm) are reported as different sizes.

Bleed

Bleed is the smallest distance on any side between the trim and the bleed area (BleedBox, or the visible page). 8 points (about 2.8 mm) or more passes; less is reported as too small. If there's no trim size, or the trim size just repeats the page size, but the page is exactly a standard size plus 0.125 in, 3 mm, 5 mm or 0.25 in on every side, the trim size is inferred and the report says so.

For pages without bleed, each page is rendered and the pixels just inside the edge are sampled. If more than 3% of an edge has non-white artwork, that edge is reported as running to the edge. For pages with bleed, the bleed area is sampled too; if artwork reaches the trim line but the bleed next to it is mostly empty, the bleed is reported as empty.

Text near the edge

Text positions come from the PDF's text layer, using each font's ascent and descent where available. Any text closer than 0.125 in (9 points) to the trim edge is reported, and text crossing the edge is reported as a problem. Text entirely outside the trim (for example printer notes) is ignored. Text that has been converted to shapes or images can't be checked.

Image resolution

Images drawn in the page content are found, including images inside grouped objects, pattern fills and inline images, and its effective resolution is calculated from its pixel size and its placed size on the page. The lower of the horizontal and vertical values is used. Under 150 DPI is a problem and 150–224 DPI is a warning. For pages with a side longer than 17.5 in, the limits are 100 and 150 DPI. 1-bit masks, images 8 pixels or smaller on either side, and images placed smaller than 0.25 in are skipped. Images that hang off the page are labeled as cropped by the page edge; clipping inside the page isn't taken into account, and images inside annotations aren't checked.

Fonts

Each font used to draw text is checked for embedded font data. Fonts that aren't embedded are a problem, unless all of them are standard PDF base fonts (such as Helvetica or Times, including the Arial, Times New Roman and Courier New fonts Microsoft Word leaves out), which is a warning. Type 3 fonts are drawn from shapes in the file and count as embedded.

Colors and ink

Colors are classified from what's actually painted: fills, strokes, text, images and gradients. ICC-based colors are classified by their number of channels. Separation and DeviceN colors with names other than the process inks are reported as spot colors. A file that declares a PDF/X version is reported as PDF/X (not fully validated); an output intent without one is reported as colors prepared for a printing condition. Total ink is the highest C+M+Y+K sum among solid CMYK colors; above 300% is a warning. Ink in photos isn't measured.

Other print hazards

Transparency (partial opacity, soft masks and blend modes; fully invisible objects are ignored), overprint settings, form fields, comments set to print, layers, security restrictions, JavaScript and attached files are reported with what they mean for printing. Files that are cut off (for example an interrupted download) or have missing parts are reported, and results that depend on the missing parts aren't claimed.

Automatic fixes

Only two fixes are offered, because only these are exact:

  • Mark the trim size when the page is a standard size plus bleed but the trim isn't declared or just repeats the page size.
  • Correct contradictory page boxes, where the trim or bleed area extends past the page.

Fixes are written as an incremental update: the original file's bytes are kept unchanged and the corrected page settings are appended, then the result is re-read to verify it. Bleed isn't generated, images aren't upscaled and colors aren't converted, because each would change the artwork.

What isn't checked

  • Full PDF/X or PDF/A compliance.
  • Ink coverage inside photos, overprint preview, and trapping.
  • Hairlines, minimum text size, and very thin strokes.
  • Fold lines, panels, dielines and imposition.
  • Spelling, layout, and whether the design looks right.
  • A specific printer's requirements. Always check their specifications and the proof.

Tested with

The checks are tested against PDFs produced by Google Chrome, Ghostscript (including PDF/X-3 with an output intent), pdf-lib and qpdf (encrypted files), covering RGB, CMYK, spot colors, missing fonts, low-resolution images, bleed with and without a declared trim size, and damaged files. They are also tested against 22 real-world PDFs, including 12 real Canva exports (with and without crop marks and bleed, CMYK with an output intent, large posters, Type 3 fonts and cut-off downloads) and files from Microsoft Word, Affinity Publisher and Designer, Illustrator, InDesign and Scribus. Image resolution, page boxes and font embedding were cross-checked with poppler, and edge findings against Ghostscript renders. Canva's own export behavior can change over time.