Another poster here suggested the High Capacity Color Barcode as well, which ought to already have some implementations available somewhere and sports an even higher data density if you’re willing (or able) to deal with color.
QR codes are limited to being square in aspect ratio (other than the not terribly helpful “micro rectangular QR” format) and have a maximum payload of ~3kB each. This may not be a great fit for plain consumer paper with a rectangular aspect, and you’d need to jigger some manner of batch reader so’s you don’t drive yourself insane recovering the data. Neither is an insurmountable problem; I’m just thinking out loud, here.
IphtashuFitz@lemmy.world 1 day ago
I’d be wary of one or more colors fading over time unless you are VERY careful with how you print these. Being monochromatic, QR codes don’t have such issues. It would likely also be easier to recover a faded QR code than a colored bar code.