Field guide / Print preflight
Run an online print preflight before upload
Use a practical online print preflight checklist to review page size, bleed, fonts, images, color and final PDF output before sending artwork.
Confirm the printer's specification, trim and bleed, safe area, page count, fonts, image resolution, color setup, overprint, dielines, PDF preset, file name and final visual proof. Browser tools can verify dimensions and image resolution, but the printer's own preflight remains the final authority.
Four stages of print preflight
1–2. Begin with the printer's specification
Preflight starts before opening an online checker. Obtain the printer's required trim size, bleed amount, safe area, color mode, accepted spot colors and preferred PDF standard. If the job uses a supplied template or packaging dieline, confirm its revision and keep it at exactly 100% scale.
Write these requirements beside the job. A generic result such as 300 PPI or 3 mm bleed is only a planning value; the production supplier's specification overrides it. Confirm whether crop marks are required, because many upload portals want bleed but do not want printer marks.
- Check 1: Record trim size, bleed and safe-area requirements.
- Check 2: Confirm color, PDF preset and mark requirements.
3–5. Verify document geometry and page structure
Make sure the layout document uses the finished trim size rather than the bleed size. Extend backgrounds through the bleed while keeping important text, logos and barcodes inside the safe area. For a PDF, inspect every page dimension and orientation; mixed sizes often indicate an accidental export or a file assembled from different sources.
Review page order and page count against the job. Blank pages may be intentional in books but accidental in flyers or handouts. When combining PDFs, use copies of the originals and inspect the merged output rather than assuming the input order was preserved.
- Check 3: Match document trim size to the order.
- Check 4: Extend edge artwork through bleed and protect the safe area.
- Check 5: Verify page size, orientation, count and order.
6–8. Inspect fonts, links and technical layers
Resolve missing fonts and broken image links before export. Embed fonts in the production PDF unless the printer explicitly requests outlined type. Outlining can prevent substitution but makes text harder to edit and can alter complex typography, so keep an editable master file.
Packaging and specialty print files may contain cut paths, folds, varnish, foil or white ink as named spot-color layers. Confirm that technical lines have the correct overprint and visibility settings. Do not flatten or recolor a dieline simply because it appears on screen; follow the converter's layer instructions.
- Check 6: Resolve missing fonts and linked assets.
- Check 7: Confirm font embedding or approved outlining.
- Check 8: Verify dielines, spot layers and overprint settings.
9–10. Check effective image resolution and color
Calculate effective PPI at the placed print size, not only the source file's metadata value. Inspect the final crop and look for JPEG blocks, blur, sharpening halos and upscaling artifacts. Vector logos and live type should remain vector when the workflow permits it.
Use the printer's requested color space and profile. A file can look acceptable on a bright display but print darker or less saturated. Review separation preview for accidental spot colors, rich black recipes, white objects set to overprint and any color that should not appear on a plate.
- Check 9: Verify effective PPI and visual image quality.
- Check 10: Review color spaces, profiles, spots and separations.
11–12. Export once, then proof the exported PDF
Export with the printer's preset, then treat the PDF as a new deliverable that must be inspected independently. Open it outside the layout application, check page boxes and dimensions, zoom into type and fine rules, and review every page from first to last. The source document being correct does not guarantee that export settings were correct.
Use a clear file name with job, size and revision information. Keep the editable source and previous approved version separate from the upload file. For high-value work, request a digital or physical proof and retain the printer's automated preflight report with the job record.
- Check 11: Inspect the exported PDF at high zoom and in page order.
- Check 12: Name, version and archive the exact file being uploaded.
Put the method to work