And once you've got the QR codes on, you setup a pi with a camera than can read them and give you the results, maybe with a red/yellow/green LED for age :-)
Brilliant idea. I really should start labeling stuff like that, I've used some handwritten notes but QR codes sound a lot easier to plop in a database.
Are they full data containing QR's (they have all info text contained within the code) or do they link to an external database/software that tracks them?
Glad you like the idea. I actually started selling these QR Codes readily printed, but you can also do it yourself with some technical skills. The QR Codes are generated and printed before their purpose and content is known. You just scan a new code and have a markdown / rich text editor where you can put any text and attach images or files.
Yes, I use Avery Labels. Still looking for an alternative because I would like to have smaller ones so I can stick them to very small stuff but the smallest square label I have found so far is 20x20mm