A QR Code that does not scan is worse than no QR Code at all: people try twice and give up. The problem is almost never the code itself but the printing: too small, low contrast, glare, a margin eaten by the trim. This guide collects the rules that matter before you send a hundred copies to the printer.
1. The right size depends on distance
The rule of thumb: the side of the QR Code should be at least one tenth of the distance it is scanned from. A few references:
- Business card, label, packaging: at least 2 × 2 cm (scanned at 20 cm).
- Table, flyer, menu: 3-4 cm (scanned at 30-40 cm).
- A4 or A3 poster in a window: 8-10 cm (scanned at 1 m).
- Large poster or billboard: 20 cm and more (scanned from a few metres).
The longer the content, the denser the pattern and the more space it needs. A dynamic QR Code only contains a short address, so it stays simple and scans well even when small.
2. Contrast: dark on light
- Dark code on a light background. The opposite (light on dark) is not read by every phone.
- If you use brand colors, pick the darkest shade for the code and a very light one for the background.
- No images, photos or textures behind the code.
- Careful with gradients: fine if the whole code stays dark, not if part of it gets too light.
3. The white margin around it
The standard asks for empty space around the code, the “quiet zone”, of at least 4 modules (the small squares it is made of). Do not let text, lines or borders touch the code, and leave a margin towards the trim edge too: cutting machines are off by a few millimetres.
4. The file format
- SVG or PDF (vector) for professional printing: they stay sharp at any size.
- PNG for the web, emails or office printing; download it large and do not enlarge it afterwards.
- Do not use a screenshot of the code and do not compress it as JPG: the edges get blurry.
5. Materials and finishes
- Matte paper or lamination: glare on glossy paper is the number one cause of failed scans.
- Avoid foils, hot stamping, embossing and varnish right on top of the code.
- On curved surfaces (bottles, mugs) keep it small relative to the curve, or it gets distorted.
- Outdoors use sun-resistant materials: a faded code loses contrast.
6. A line that says what to do
Next to the code, write what happens: “Scan to see the menu”, “Scan to save the contact”, “Join the Wi-Fi”. Many people do not know the camera is enough, and a clear line increases scans. A frame with a call to action, which you can add from the generator, does the same job.
7. Test before the print run
- Print one sample at the real size, on the real material.
- Scan it with at least two different phones, an iPhone and an Android, one recent and one old.
- Try it at the real distance and in the light of the place where it will hang, evening included.
- Check that it leads to the right page. Only then order the copies.
Quick summary
- Side of the code ≥ one tenth of the scanning distance.
- Dark on light, no busy backgrounds.
- White margin around it, away from the trim.
- SVG or PDF for print, matte finish.
- A call-to-action line and a test before printing.
You can create your code with the QR Code generator: when you save it, DenQr checks the design and rejects those that would make the code unreadable, for example with too little contrast.