What is the maximum character size of a QR code generated in the e-mark app?

There is no limitation of character size for QR codes in our app. We tested QR codes with different character sizes and even ones with 60 or 80 characters were still well readable by standard QR code readers. However, in terms of readability of the printed QR code, keep in mind that QR codes can become quite hard to scan with increasing number of characters. The readability depends also on the quality of the QR code reader on the device, mobile phone, the material it is printed on, etc.