Crystal-Clear Resealable Bag for Audio Cassettes in O-Cards 100pk

These sound pretty good, although out of the 6 or so I've run off and listened back to so far, one of them had some major dropouts that started about 4 minutes into the tape. They subsided after about 30 seconds, but who knows if they happened again later; I didn't finish listening and put the tape aside. I did re-record several times to make sure it was the tape, and flipped it over to see if the dropouts carried over. They were only on one side and happened in the same spot no matter what information was recorded there so I can only assume it was an issue with the tape itself. I hope I don't run across more of these, I don't want to have to listen to every single tape I run off all the way through before selling them to someone.