How do I print a QR code that actually scans?

Download the QR from Zebeh, print it at least 2 cm on the shortest side, keep high contrast (dark modules on a light background), and leave a quiet white margin. Do not stretch it, and do not drop a large photo into the centre if you have not tested a scan. The code should stay a URL QR — short and easy to read — not a vCard packed into the squares.