I know it sounds “boring” but it is hard to beat a good acid-free archival paper printed with a good quality ink. Stored in the right circumstances (not too humid, dark place, not on fire) it should last half a millennia easily. It is also pretty much guaranteed that whatever happens we will have the technology to read it again.

Exotics like laser engraved metal plates or ceramics might be better if you have a lot of data and can’t guarantee your storage will be fire and flood free. If you don’t have a lot of data you can also think of engraving it into stone or press it into a clay tablet and fire it. These mediums are known to be very stable even in adverse circumstances.

I guess you could consider it an "offline datastore as a service." It would be a pretty good offline storage of keys with a way to request a paper copy. Certainly issues of trust and physical security but wrapping it with encryption would be easy. Also benefit from your government's legal protections for mail. There might actually be a usecase here.

Couple fast facts:

- Current 26 * 32 = 832 cells * 6 dot braille = 4992 bits/mold/page

- Possible 28 * 34 = 952 cells * 6 dot braille = 5712 bits/mold/page

- Maybe some more headroom, but that's what is possible with current spacings

There is also Microsoft Project Silica which I recall seeing in person at their EBC playing back a movie from it https://www.microsoft.com/en-us/research/project/project-sil...

Then there is m-disc which uses the DVD+R and BD-R/BDXL standards but writing to a sort of glass rather than to the traditional medium. These are cool as they play back n regular players too. https://www.mdisc.com/

your X/Y resolution isnt going to be fantastic woth filament, but your Z is gonna really suck.

you could instead print(emboss?) like a barcode on some paper, and encase that in resin. the big benefit being that you can read it non-destructively. keep it out of the sun so whatever ink doesnt fade and you're set

There might be corner cases where 3d makes sense...but it is hard to compete with decals/stickers, and 2d steganography can also use color and saturation as additional data dimensions.

But I could be wrong.

For a small amount of data (crypto keys?), consider deep laser engraving on stainless steel. That's very durable. Or even engrave text into stainless steel with a small CNC mill.

You can engrave QR codes, bar codes, etc. But there's a lot to be said for engraving plain text.

If you want something truly long lasting you might find substractive manufacturing techniques like CNC milling better. Indeed there are solutions from companies like Cryptotag for punching cryptographic seed data into plates / blocks of titanium. Something like this could be automated with a CNC router to store a bunch more data.

Probably use a 177x177 QR code with Q or H error correction engraved (deeply). I would probably compress the data and encode it as Hex so it can be stored in alphanumeric mode on the QR. You might need a series of QRs for larger data.