Also, many tapes (depending on make and age) can
actually be so brittle that during the read the material seperates from
the transport, not a pretty sight.
--
What appears to happen is the adhesion to the previous layer of tape is
greater than to the original, and it strips the oxide and binder to clear
mylar (not a pretty sight or sound).
I have become VERY cautious when working with old floppies and tapes and
assume that I will only get one pass at recovering the data. For discs,
you want to keep the heads moving. I've crashed a LOT of disc packs by
staying on a single track too long.