Over a decade ago I was working for AWS on Glacier, we jokingly pitched an April fools day article about how Glacier stores customer data on vinyl records, and that 9 out of 10 customers preferred the feel of their data when restored.
AWS doesn't (or didn't) do April Fools day bits, so it didn't go anywhere, but the idea did amuse us in the team for a bit.
Engraving data on a titanium record would be a way to store it for many years even with exceptionally poor environmental conditions (fire, flood, locusts, plagues, what have you).
I'd heard of those but never looked them up, always thought they'd be super expensive. It's about $40 for a drive that can write them and $13 each for 100GB media. That's pretty reasonable for durable storage.
Yeah, normally it's not expensive, but since market for these discs are so small here, the prices are at exorbitant levels for M-DVDs. M-BDRs were unavailable, but they are available for reasonable prices, as I just checked.
I have drives which can burn M-DVDs, but I'd need an M-BDR drive. The ones I have doesn't support M-DISCs.
To be fair, that's not simply an archival disc, but also something explicitly intended to be readable by intelligent life elsewhere in space. The encoding of data was optimized for simplicity above all else.
AWS doesn't (or didn't) do April Fools day bits, so it didn't go anywhere, but the idea did amuse us in the team for a bit.