Back in 1971 or so, we had a PDP-5 with DECTapes, and bought 3/4" analog recorder tapes surplus to make up new tapes. It was much thinner than DECTape, and we had print-through issues of tapes that were stored for a few weeks. That seemed to clear up if the tapes were then used again. I guess the permeability was not as high as real DECTapes. Jon