I would never trust a printed on paper protractor on a high-end turntable. I’m an architect, and deal with skilled accurate drawings every day. Even with good quality printers on good heavy gauge bond paper things can be ever so slightly off. First paper shrinks and expands based on humility. Second printers don’t necessarily print perfectly, depends on how they print and to how acutely the paper mechanism rolls the paper as print, thirdly and most importantly the hole needs to be man made and when fractions of a mm count that’s too much risk. Don’t get me wrong if all you want is a generally OK alignment then maybe paper is OK but I would never trust that on the high-end turntable. Factions of a mm matter
Well, I can’t speak for the effects of "humility" or "factions of a mm," but having used a number of the Dennesen/ Feickert style protractors, I concluded they are far more prone to significant error. This is especially true because they rarely mimic the height of the playback surface. Their spindle holes are typically fixed and often have close to a whole mm of slop. You won’t find that problem with the common printable protractors. Then it’s up to the user to eyeball whether the guide rod is centered over the tonearm pivot - another potential point for egregious error. When you add these all up, you might be off by whole millimeters rather than just fractions.