How-to guides
How to proof a QR code with a print shop
Send the code as vector SVG or PDF with written instructions: do not rasterise or resample it, keep it 100% K rather than a rich-black build, never scale it down, and leave the quiet zone empty. Then ask for a hard proof at final size on the final stock, and scan the proof before signing off.
Why the shop conversation is its own step
You can do a perfect pre-flight of your own artwork and still receive unscannable print, because prepress routinely does helpful things (resampling images, converting colours, tidying blacks) that are fatal to a QR code and invisible on a PDF proof. This page is the other half of the job: what to hand over, what to say, and what to demand back.
What to send
- Vector artwork: SVG, or a PDF in which the code is live vector paths, not a placed bitmap: the reasons are laid out in why you should print from SVG. If the workflow forces raster, supply PNG at 600 DPI at final size and say so.
- The code already at final size in the layout, not "to be scaled to fit".
- A note stating the code has been verified, run it through the validator first so the payload discussion is already closed.
The instructions to give (paste these)
- Do not rasterise, resample or re-compress the QR code element.
- Print the code as 100% K only: do not convert it to a rich black or 4-colour build.
- Do not scale the code below its placed size, or resize it independently of its white margin.
- The white margin around the code (4 modules) is part of the artwork, no text, trapping, artwork or fold within it.
- No spot varnish over the code area; tell us if the stock or laminate is gloss.
Each line closes a real failure: resampling softens module edges; a rich black build (e.g. C60 M40 Y40 K100) puts four plates under fine modules, and any misregistration fringes them, colour management details in CMYK printing; scaling breaks the size-for-distance maths (recheck with the size calculator if dimensions change); a violated quiet zone is the most common print-side kill; and gloss or varnish creates glare angles: see laminate and varnish effects. If the code sits near a trim edge, confirm it clears the cut and fold lines per bleed, trim and safe area.
What to ask for back
A hard proof at final size on the final stock, for offset work, a wet proof from the actual plates if the run justifies it. A soft (PDF) proof cannot show you dot gain, stock colour, laminate glare or registration, which are precisely the things that kill codes. For a digital run, one printed sample from the production device is cheap and answers everything.
Sign-off: scan the proof, then sign
| Check on the physical proof | Pass |
|---|---|
| Scans with two phones, one of them old | ☐ |
| Scans at the intended viewing distance | ☐ |
| Scans under gloss/glare lighting if stock is coated | ☐ |
| Measured size matches the layout | ☐ |
| Quiet zone visually intact, nothing encroaching | ☐ |
| Code black looks solid (no visible rosette/pattern in modules) | ☐ |
Only then approve the run. A print shop is not being difficult about any of this. These are unusual requirements for them, because almost no other artwork element fails from being helpfully "improved". Say it explicitly, get the proof, scan the proof.
FAQ
What file should I give a print shop for a QR code?
Vector: SVG or a PDF where the code is paths, placed at final size. If raster is unavoidable, a 600 DPI PNG at final size with an explicit no-resampling instruction.
Why should a QR code be 100% K and not rich black?
Rich black lays the modules across four plates, and any misregistration between them fringes the module edges. Single-plate 100% K keeps edges as sharp as the press can make them.
What is a wet proof and do I need one?
A proof pulled with the actual inks and plates on the production stock. For large offset runs it is the only proof that shows real dot gain and registration on your code; for digital runs, a sample from the production printer serves the same purpose.
What do I check before signing off a print proof?
Scan the physical proof with at least two phones from the real viewing distance, check the code's measured size, confirm the quiet zone is untouched, and test under glare if the stock is coated or laminated.
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Related
- 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…
- QR codes in CMYK print, Keep modules at 100% K on a single plate. Four-colour black needs four plates in register, and ±0.1 mm of misregistration fringes every module edge.
- Why you should print QR codes from SVG, Vector QR codes rasterise at the press's native resolution with exact module edges. The PNG-resample chain is how codes that looked sharp on screen die in print.
- How to test a QR code before printing, Verify it decodes, check the payload character by character, print at final size, scan with old phones in bad light, and probe the damage margin. A checklist.