does videotape actually deteriorate or is it just the images that fade so you can retape over and get a good quality image again?
Yes. But seriously… They can deteriorate if used a lot. The magnetic material can chip or flake off by running through the vcr mechanism. I have tapes that are 17 years old that still look pretty good. The majority of my tapes over 10 years old were recorded on a two head machine and consequently don’t look THAT good on more modern four head machines. That’s why I keep an old two head on hand when I want/need to watch them. I suppose the tapes could become de-magnetized over long periods of time. When the price of recordable DVD machines come down out of the stratosphere, I’ll transfer the material that is extremely difficult to replace (my MST3K collection is first in line!) to DVD’s. At least that way, the deteriorization will be slowed. I’ve been taping for 17 years now and have yet to have recorded material “fade” off a tape. Some of my Kodak tapes have the tendancy to pop their leader tapes, so I’m extra careful when handling them.
Sony has said that at 15 years a video cassette starts turning to fuzz…& eventually becomes nothing but that.