you are right a stack of printed qr codes is better

No, that's too easily machine-read. Print it in a fancy calligraphy font or one with ambiguous characters.

Reminds me of Lavabit where the US wanted the encryption keys and they printed them out in a 4 point font :D

https://en.wikipedia.org/wiki/Lavabit#Legacy

That's too convenient, cameras can read many qr codes at a time. Encode the binary on some punch cards.

Pretty sure cameras can be used to read punchcards too.

This sounds like a fun project. Somebody already did it, apparently: https://hackaday.com/2012/07/30/reading-punch-cards-with-an-...

They don't have to be cheap.