A QR-code is a 2 dimensional code that can include up to 7089 numerical or 4296 alphanumerical characters. The smallest size is 21 x 21 cells, the largest is 177 x 177. The size of the QR-code depends on the size of the data. This can be an ascending number or it can be an URL with a link to a website.
The biggest advantage of a QR-code is that it is perfectly readable with both a scanner or a camera and it stays readable even if 30% of the cells are damaged. This is in sharp contrast with the traditional barcode.
You can opt for a vast, identical QR-code or a variable QR-code. An identical QR-code is printed during the digital or offset printing process. A variable QR-code is part of personalisation and is applied by thermal printing.