What decided the backing paper print-through came from was poor ink on the paper affecting the emulsion. This assumes your "red window" isn't an issue, which was on an old Brownie I have. Black gaffer tape fixes that.
Obviously this isn't ever a problem with the sheet film.
The decision that it was the ink interacting with the emulsion - and I could be completely wrong - made me realize just how complex a boutique film plant would be to produce small runs of high quality film. The number of things that have to be "right" to make a first rate film is mind-numbing. OTOH it is completely possible to pour your own plates in your own darkroom.