Before you send a QR code to print
A code that scans perfectly on screen often fails on paper. Business cards and posters cannot be taken back once printed, so here is what to check, in order, before handing off the file.
1. Send vectors
Raster images like PNG blur at the edges when scaled, and a printer resizing them can smear the modules. Send an SVG or PDF so the edges stay sharp at any size. That is what the SVG download on this site is for.
If PNG is your only option, export it large enough to reach at least 300 dpi at the final printed size.
2. Black should be one ink
Process printing layers cyan, magenta, yellow and black. If your design tool specifies a rich black made from all four, the slightest plate misalignment puts coloured fringes around every module. Ask for the code to be printed in 100 percent black (K) only. Any printer will understand “QR in K100 only”.
3. Minimum size
A module should be larger than 0.4mm for a typical phone camera. Larger versions have more modules, so at the same printed size each module gets smaller.
| Version | Modules | Minimum | On a business card |
|---|---|---|---|
| V2 | 25 | 20mm | Comfortable |
| V4 | 33 | 24mm | Fine |
| V7 | 45 | 30mm | Tight |
| V10 | 57 | 38mm | Not recommended |
If space is tight, set emptiness to ‘Standard’ on this site. It keeps the version small so each module stays large.
4. Keep the border
A QR code needs a clear border four modules wide. Designers often trim it or push other elements right against the code to save space. The saved file already includes the border, so ask for the whole file, border and all, to be treated as the code's size.
5. Ink spread
Uncoated stock, especially recycled or kraft paper, soaks up ink and makes dots grow during printing. When neighbouring modules merge, the scanner cannot tell them apart. On such papers, slightly smaller round dots (85 to 90 percent) leave gaps even after spreading and are more reliable. Do not go below 80 percent though. The measurements are in making it scan reliably.
6. Think about where it lands
- Folds. A code across a leaflet fold will not scan.
- Curves. Cups, bottles and tubes bend the code. Print smaller or raise the error level.
- Gloss. Reflections wipe out modules. Leave the code area matte, or raise the error level for headroom.
- Distance. For posters read from afar, a common rule is a code side of about one tenth of the scanning distance. Two metres away means 20 centimetres.
Nothing beats a test print. Print one copy on the real stock at the real size and scan it with several phones. When you ask the printer for a proof, make sure the side with the code is included.
Checklist before handoff
- Is it an SVG or PDF vector file?
- Are the modules single-ink 100 percent black?
- Is the printed size at or above the minimum for its version?
- Is the four-module border intact?
- Does it avoid folds, curves and gloss?
- Has a test print on the real paper been scanned?