QR codes by industry

What to actually print, where to put it, and the specific way codes fail in each trade. These are written around the physical surface the code ends up on, because that is what decides whether it scans.

The thing every one of these has in common

Whatever the trade, the expensive mistake is the same: printing a code onto something you cannot cheaply reprint, and then losing control of where it points. That happens through a dead destination URL, or through a platform that stops resolving codes when a subscription lapses.

Use dynamic codes so the destination stays editable, point them at pages on a domain you control where you can, and check what your platform's terms say about lapsed accounts before you print anything. More on that here.

The three numbers that decide whether a code scans

Whatever the trade, the physical failures come down to the same arithmetic, and it is worth knowing before you send anything to a printer:

  • Printed size versus scanning distance. A code wants to be roughly a tenth of the distance it is read from. Arm's length is 20–30mm; a yard sign read from a car at four metres wants 40cm, which is larger than most people print.
  • Module size. Printed width divided by module count. Below about 0.5mm per module, phone cameras and printing processes both start to struggle — which is why a long URL on a small label fails even when the code looks generously sized.
  • The quiet zone. Four modules of blank margin, every side. It is the rule designers break most often, and the one scanners depend on to find the code at all.

Our generator shows the version, module count and a recommended minimum print size for your specific code as you build it, so none of this has to be worked out by hand. The glossary explains each term properly.