i work in a planetarium that opened in 1966. we keep EVERYTHING. i still have show tapes (r to r) from 1966 on the shelf. i've noticed that the really old tapes have help up ok but the stuff from the 80's is all gooing up.

is this gooey phenomenon happening to cassettes as well?

Hi,

Many of the back coated tapes of the 1970's have had sticky-shed issues. Worst of these tapes were Ampex 406, 407, 456, and 457. Some Scotch stock had this issue. Mainly 250 and 996. Maxell didn't. Such tapes can be baked if needed by knowledgeable parties so they can be transferred to other media. Please let us know what tape has this issue so we can assist you. Cassette tapes didn't have this issue, only open reel tapes.