You make great points! I appreciate the detail of the comment, and I don't particularly disagree with any of it. I think someone else mentioned gravestones that are etched and filled with black, so your suggestion of just doing that with sensible scales and fonts seems like a slam dunk, to me.

Bummer that it doesn't really seem feasible for a hobbyist, though. I take your meaning with the wax and such, but I think my solution would just be to go bigger and store less data. And I mean bigger like, 20 characters per print bed, or something. But then, at that scale, maybe a QR code would hold up well enough in plastic, too?

Overall, I think I've mostly learned that "archiving format" is a broad term that really needs to be collapsed by describing how the archive will be stored (and what extremes/complications to expect). In any case, thanks for the links and again for the detailed discussion!