Pre-press checklist for QR codes

Eight checks before any print run: scan a physical proof from the real distance, verify size against the ten-to-one rule, confirm the four-module quiet zone, keep the code clear of folds and trim, specify matt, supply vector, verify luminance contrast, and confirm the destination will still resolve.

The checklist

1. Scan a physical proof. On the final stock, with the final finish, from the distance the audience will use, under lighting like the real environment. Not from a screen, not at 10 cm under a desk lamp. This one check catches most of the rest.

2. Size against the ten-to-one rule. Printed width ≥ scanning distance ÷ 10, and each module at or above the floor for your substrate. Use the size calculator.

3. Quiet zone. Four modules of clear space on every side. Nothing in it — no text, no rule, no coloured panel, no photograph. Note that four modules scales with the code, so a fixed millimetre padding is wrong at one size or the other.

4. Folds, trim and perforations. At least 8 mm clearance. A crease through the pattern breaks it optically and geometrically.

5. Finish. Matt over the code. No gloss lamination, no spot UV, no varnish, no foil. If the piece is glossy overall, ask for a matt spot over the code.

6. Vector artwork. SVG or PDF placed at final size. If raster is unavoidable, final size × 300 dpi, PNG, no upscaling, no JPEG.

7. Contrast in the final colour space. Modules at 100% K on paper white unless you have measured the luminance difference of an alternative. Brand colours often convert badly to CMYK. Verify with the validator.

8. The destination. Does it resolve? Is it mobile-friendly and fast on cellular? Will it still resolve in three years? For anything with a long life, point at a stable path on your own domain and record the redirect where nobody will delete it during a future rebuild.

Two extra checks for large runs

Decode-verify the whole batch. For variable-data work — unique coupons, per-store codes — run every code through a decoder before the press starts. A systematic encoding error found after 20,000 labels is an expensive afternoon. Our bulk tool verifies each code as it generates.

Print a stress proof. Print the code at 90%, 80% and 70% of the intended size and scan each. If the intended size only just works, you have no margin for press variation.

FAQ

How do I test a QR code before printing?

Print a proof at final size on the final stock with the final finish, and scan it from the real distance under realistic lighting. Screen testing does not catch ink spread, glare or upscaling.

What clearance does a QR code need from a fold?

At least 8 mm beyond the quiet zone. A crease through the code scatters light and puts the two halves at different angles to the camera.

Should QR codes be printed in black or a brand colour?

100% K on paper white unless you have verified the luminance contrast of the alternative in the final colour space. Colour conversion frequently reduces contrast below the working threshold.

How do I check thousands of codes before printing?

Generate them through a tool that decode-verifies each one, and spot-check a physical proof. A systematic error found after the run is far more expensive than the check.