I have been working in long term storage for many years. I never understood why we cant just 3d-print binary code on thin clay tablets and then burn them for long term storage. Clay tablets are readable for thousands of years.

Stone - and more usefully, clay - last almost forever, but they're impractical for digital storage, since there's no useful way of imprinting on them that isn't very low density, unlike paper.

Unless we could improvise something with old-school dot matrix impact heads to print on clay - I wonder if anyone has tried.

1 line of 80col text per card is pretty awful though, and then you bring back all the horrors of 60s card sequencing but for bigger files.

Some kind of 'barcode' encoding, with heavy error correction, would probably be better. I've seen attempts that claim 500kB per side using a largely unmodified QR code system, but I suspect better could be achieved - the method of scanning is probably going to be the bottleneck anyway.