Provided that the information one wants to keep safe is sensitive and important long term, there are two main issues with printing (either text, QRCode, or anything):
* (paranoia) can you trust your printer not to leak the secret? (either in local memory, or to send it to its cloud mother-ship?) you can encrypt your information and print that, but then you are back to square one: where do you backup the password;
* and most importantly, long term resilience: given that with normal printers you can only print on soft materials (like paper, or perhaps plastic), they won't last floods, fire, and other unlikely events; (even if one laser etches some information on a steel sheet, I don't know how resistant to abrasions it is;)
However, by actually drilling holes into a metal sheet, the only way to permanently make the data irrecoverable, is to destroy the object completely.
For point 1 I recall the creator of Age, Filippo Valsorda suggesting something similar:
>The .age-recipients files also include the public key for an offline disaster recovery key. I generated the key with age-keygen, encrypted it with age -p, printed the ciphertext as a QR code, and wrote the random passphrase in pen. This is a bit convoluted, but I don’t trust printers. All this was done in a tmpfs, so nothing reached storage. Only had to do this once, and have been using that key as the anchor for all my disaster recovery data.
https://words.filippo.io/dispatches/passage/
* (paranoia) can you trust your printer not to leak the secret? (either in local memory, or to send it to its cloud mother-ship?) you can encrypt your information and print that, but then you are back to square one: where do you backup the password;
* and most importantly, long term resilience: given that with normal printers you can only print on soft materials (like paper, or perhaps plastic), they won't last floods, fire, and other unlikely events; (even if one laser etches some information on a steel sheet, I don't know how resistant to abrasions it is;)
However, by actually drilling holes into a metal sheet, the only way to permanently make the data irrecoverable, is to destroy the object completely.