[Intralexical]

> But... is anyone doing that with a 3D printer? Or a CNC machine, for that matter?

Do you count plaques on public landmarks?

> I think some of the other answered showed that people are, it's just pretty niche. Not something a hobbyist can (currently) do, but definitely the same idea at a production scale.

Definitely is doable, having done it myself. You can probably hit your century target using the more specialized FDM/SLA/DLP hobby feedstock, if you can guarantee climate-controlled storage. Millenia if you shell out high double to low triple digits for a print service with fancy industrial machines, or if you combine a home printer with ceramics or metal jewellery skills.