QR failures on packaging are almost never the standard's fault; they are artwork accidents between the generator and the plate. This checklist is the ten-minute pass that catches them while they are free to fix.
1. Quiet zone intact
Four modules of clear space on all four sides, part of the symbol itself. Borders, text, die-cuts and background art must all stay out. If the file came from the generator, the quiet zone is baked in; verify nobody cropped tight for layout.
2. Contrast and polarity
Dark modules on a light background, never the reverse; scanners assume that polarity. Brand-colored modules are fine while contrast stays high, measured against the actual substrate and inks. Metallic films, varnishes and shrink materials all shift readings, which is what printed proofs are for.
3. Size and module integrity
Confirm the printed width matches the spec from the size rules, and that the file is vector. A designer scaling a PNG down by 7 percent resamples every module edge, and a code that scans on screen dies on film. Scale vector artwork up freely, never below minimum size.
4. The two symbols agree
The single most expensive failure: linear barcode digits and the GTIN inside the QR disagreeing after a late SKU swap or a copy-paste between label variants. Onpack's artwork verification decodes both from the artwork and compares them, one API call, before plates exist. Pair it with the 50 mm placement check.
5. Placement survives the physical pack
Check the code against the real object, not the flat dieline: seams, folds, tight curvature, shrink distortion and glued overlaps all eat symbols. Codes near edges get damaged in transit; codes under the label overlap disappear entirely.
6. The destination is live before the run
Scan the proof and watch it resolve, as a phone and as a machine. A perfect symbol pointing at nothing ships embarrassment at print scale; registration takes minutes and the destination stays editable forever after.
The habit that replaces the checklist
Make scan-the-proof a signoff gate, the same signature that approves color. Every failure above is discoverable by one person with one phone and one printed sheet, which is the entire economics of pre-press against reprint.
Common questions
What is the most common artwork failure for QR codes?
Trimmed quiet zones and inverted colors are the classics; the most expensive is the linear barcode and the QR disagreeing on the GTIN, which invalidates the whole run.
Can the QR be recolored to match the brand?
Within reason: dark modules on light background with strong contrast. Never inverted, never over busy imagery, and test the actual inks, not screen values.
What resolution should the artwork file be?
Vector. Supply the SVG and the module edges stay crisp at any size; rasterizing invites resampling artifacts that soften edges and kill scans.
How do I verify the final artwork before plates?
Scan a printed proof at final size with several phones, and run the artwork verification that decodes both symbols and compares their GTINs. Onpack provides that check via the API.