FWIW, QR isn't the best option for the real world - it's extremely fragile and susceptible to damage compared to DataMatrix, the other commonly used 2D symbology. DoD uses DataMatrix for marking all aircraft and other components for traceability, for instance.

I've used it on oilfield prototypes just printed on weatherpoof laser labels, and they're still readable even with big gouges and divots missing. By contrast, despite the redundancy, you can scrog a QR code with a single unfortunately placed scratch. (As I reconfirmed out this week trying to read the wiki/docs link for a secondhand laser cutting module I picked up: a screw on the rail had dragged through the QR code in a horizontal line - not through the timing section, but enough to make it unreadable. Fortunately, the model is identifiable visually on the mfr's site, so I can be sure what kind of safety goggles I need!)