That information about tape manufacture quoted above doesn't sound right to me. Rather, in the mid-1970s there was a difference between Nakamichi and EVERYONE ELSE IN THE WORLD regarding the correct playback equalization for type II tapes and beyond. Nakamichi decks played such tapes back about 2 dB brighter (and a little noisier) than all other deck manufacturers. This was of course used in hifi showrooms to show the "audible superiority" of Nakamichi decks--bring in your favorite cassettes and compare; you hear more musical detail on a Nakamichi! --until eventually they realized that this was undermining them (tapes recorded on their decks sounded dull on all other decks, after all; you can't have one without the other), and they brought their decks' response to very nearly the standard that EVERYONE ELSE IN THE WORLD had been following all along, including other Japanese brands such as Sony and TEAC.
I made hundreds of serious classical and documentary recordings on cassettes all during the 1970s. I still have many of those tapes, and during the past several years have transferred or re-transferred most of them. In the 1970s I favored type II tapes (e.g. TDK "Super Avilyn", or sometimes BASF CrO2 C-120s which were the only type II C-120s I could find) because of their superior high frequency headroom and lower noise. But I wish now that I had used type I tapes instead, because the print-through on the type IIs is very distracting in some cases. There's good hardware and software for moderating tape hiss nowadays, more than enough to make up the dynamic range difference. But nothing can cure print, and it only gets worse with time in storage.
I had good experience with type IV (metal) tape on decks that were properly designed to record on it (it required substantially higher bias current than the other types), but I didn't use enough of it to form an opinion about whether it has print-through problems or not.
--best regards