cyvideo
Veteran
M-Disc (also mfr under lic by Ritek and Verbatim) with claims 1,000 year life and comes in up to 100GB BDXL formats.
FWIW, they have some videos on the relative "life" of other medias including some advanced aging test
That's exactly what I'm using for family archive storage. Some of the wider family archive footage is film-based from the 1930s onward so that's why I chose to archive to Verbatim M discs. It's irreplaceable. That footage along with all the wider family's later old 8mm/Super 8 and some 16mm right through to the family's VHS and DV days is now going from HDD to these M discs. Nothing really scientific but what made me move to M disks from regular Taiyo Yuden and Verbatim LTH discs for archiving was this rather odd review. Quite interesting though.
Chris Young
http://www.microscopy-uk.org.uk/mag...-uk.org.uk/mag/artsep16/mol-mdisc-review.html
The discs
https://www.verbatim.com/subcat/optical-media/m-disc/m-disc-bd-r/