Practical starting sizes
- 3 cm wide
- 10 cm wide
- 30 cm wide
| Use case | Typical scan distance | Practical starting size |
|---|---|---|
| Business card, small label | 15–25 cm | 2–3 cm |
| Table tent, counter card | 25–40 cm | 3–5 cm |
| Flyer, handout | 25–40 cm | 3–5 cm |
| Small poster | 0.5–1 m | 5–10 cm |
| Window sign | 1–2 m | 10–20 cm |
| Trade show backdrop | 2–4 m | 20–40 cm |
| Large signage | 5 m and beyond | 50 cm and up |
Go larger than the table when:
- the code is visually dense because it encodes a long URL;
- the surface is glossy or curved;
- lighting is poor or uneven;
- the print process is rough — screen printing, textured stock, low-resolution labels;
- a logo covers part of the pattern;
- failure would be expensive to correct.
Why distance decides everything else
A phone camera has to resolve the individual modules — the small squares — inside the pattern. As the viewer moves back, each module occupies fewer pixels in the camera image. Below a certain point the camera can no longer separate one module from its neighbour, and decoding fails even though the poster still looks perfectly sharp to a person.
That is why billboard codes have to be physically enormous, and why the useful question is never “is 2 cm enough?” but “how far away will someone realistically be standing?”
Module density: two codes, same width, different odds
Two QR codes can be the same physical width and contain very different numbers of modules. More encoded data means more modules, which means each module is physically smaller at the same overall size — and smaller modules are exactly what fails at distance.
This is a quiet advantage of dynamic codes for print. The pattern encodes a short redirect rather than a long URL carrying campaign parameters, so it can be less dense at the same width. Worth knowing; not a guarantee, and not a reason on its own to choose dynamic.
The empty space around the code is part of the code
A QR symbol needs clear margin so a scanner can tell where the pattern begins. DENSO WAVE, which developed the QR Code and publishes its technical documentation, specifies a margin of at least four modules on every side.
The four-module margin is technical guidance from the format’s originator. The 10:1 width-to-distance rule further up is a practical planning heuristic with no standards body behind it. Treat the first as a requirement and the second as a first draft that a printed proof either confirms or refuses.
The practical consequence is a conversation designers have with themselves at some point in every layout: that white space around the code is not spare. Text, borders, icons, photos, decorative frames and other dark shapes pressed up against the symbol can remove the very thing that makes it reliably detectable.
Contrast beats brand colour, and logos need testing
Dark modules on a light background, with strong contrast, is the safe default. What breaks it: light on light, a dark background with barely-darker modules, photographic backgrounds, and gradients that leave part of the code low-contrast.
A code that matches the brand palette perfectly and does not scan is not a compromise. It is a failed design.
Logos
A centre logo covers part of the pattern. Error correction tolerates some obstruction, but how much depends on the code’s density, the correction level, whether the logo sits on a plate, the contrast at its edges, and how the renderer positions it.
“It scanned once on my iPhone” is not evidence for twenty thousand printed packages. Test more than one handset, at the final physical size, under the real lighting, from the real distance.
SVG, PNG and PDF
| Format | Best for | The thing that catches people out |
|---|---|---|
| SVG | Anything that may be resized in a design workflow | Nothing much — this is the safe default for print |
| PNG | Raster workflows that require it | Whether there are enough pixels at the FINAL physical size |
| Printer or layout workflows expecting a document | PDF does not automatically mean vector — check the proof |
The DPI arithmetic for PNG
If a printer asks for 300 DPI, the requirement is pixels = print inches × 300:
| Printed width | Pixels needed at 300 DPI |
|---|---|
| 1 inch (2.5 cm) | 300 px |
| 2 inches (5 cm) | 600 px |
| 4 inches (10 cm) | 1,200 px |
| 12 inches (30 cm) | 3,600 px |
A 500 × 500 PNG printed at one inch is fine. The same file printed at ten inches is not, and setting the document DPI does not conjure the missing pixels. If large-format scaling is even possible, use SVG and stop thinking about it.
Surfaces that break otherwise good codes
| Surface | What goes wrong |
|---|---|
| Glossy lamination | Reflections wash out modules under overhead light |
| Curved packaging | The camera sees geometric distortion, worst at the edges |
| Folds and seams | A structural break can cross a finder pattern or timing row |
| Transparent material | Whatever is behind the pack becomes the effective background |
| Textured or uncoated paper | Small modules lose clean edges as ink spreads |
| Outdoor exposure | Fading, dirt and scratches erode contrast over months |
The digital file can be flawless while the physical deployment fails. Only the proof knows.
A preflight test before any large print run
- Verify the destination loads on a phone — HTTPS, no login wall, no redirect chain.
- Confirm whether each code is static or dynamic, and who can change it later.
- Export the production format: SVG if the artwork may be resized.
- Place it in the layout at the final physical size.
- Preserve the quiet zone — nothing inside the clear margin.
- Print one real proof on the real stock.
- Scan it from the intended minimum and maximum distance.
- Test on at least two different phones.
- Test under the lighting the asset will actually live in.
- Test any logo or colour treatment on the printed proof, not on screen.
- If the code is dynamic, confirm the destination once more after the proof.
- Only then approve mass production.
Frequently asked questions
What is the minimum QR code size for print?
What is the 10:1 QR code rule?
Should I use PNG or SVG for printing?
Does 300 DPI guarantee the QR will scan?
Does adding a logo make a QR harder to scan?
Can a dynamic QR code be smaller than a static one?
Scannable artwork and controllable routing are two separate problems, and a large print run needs both. Dynamic routing does nothing for a code printed too small — but it does mean a destination that changes after the run does not force the reprint that sizing errors do.
Preparing a batch for print?
Validate the destinations, preview the design, and download PNG, SVG or PDF at production size — then proof one physically before the run.