Maybe
photographic film quality "paper tape" is the answer. The other
solution may be photographic film floppy disks. I'd better get right off to
my patent attorney and file.
Mylar punched paper tape has a VERY long lifetime and is even human
readable (well sorta ;)).
What ever happened to the really high density laser punched mylar/paper
tape that was being talked about so much a few years ago? Much higher
density than magnetic tape, and very very long archival life.