I've told people to not reuse tapes. I've implored them not to reuse tapes. I've cautioned people about the dangers of reusing tapes.
People still reuse their tapes.
In fact, a couple weeks back I was asked to shoot a live event at my church. Nothing fancy; just show up and shoot. They asked if I needed anything, like tapes. I told them that would be nice (save me a few bucks) and gave them the specifications.
If this had been an important shoot I would have brought my own tapes. It wasn't, so I didn't. I was handed two used tapes. In fact, it seemed to me that these tapes had probably been reused a few times before.
And this is the result:
Tapes are hearty, sure, but they are still prone to problems. After all, it's just little particles affixed to a flexible piece of plastic. Just like the audio cassette tapes of old, as you play/record/re-record the quality deteriorates.
So, again: Don't reuse tapes.
Granted, you may get artifacts from other sources even on brand new tapes, but reusing your tape media greatly increases your chances of lost or corrupted data.
Your Media Production Mentor