ursusmajor,
both bare shaft tuning & paper tuning are really an advanced method, and only work well for those who have mastered a fairly consistent form in their shooting.
The tears in the paper will vary from one to another due to differences in their style & form, and for those who fluctuate in their form the tear will change every time. Even something as simple as a grip pressure change will change the results of the tear. Same goes for bare shaft readings.
You may very well be one of those who have a very consistent form. If so, tune your rigs following bare shaft group tuning & visual affirmations, then shoot through the paper to see what kind of tear it gives you. That will be the tear your looking for from then on.
Once again - as SAVIOUR68 said - 12 to 15 ft from the paper seems to give the most accurate paper tune readings, because that is the distance the arrow is normally recovering from it's initial paradox.