I do have something of a clue. All of my primed leaf is strung in pairs, back-to-back, with each pair spaced 0.5 to 1" apart. I typically grow ~250 plants. As Knucks points out, it depends on your average humidity in the curing area, and specifically during the time that a particular batch of leaf is being cured, as well as the leaf variety. Some leaf stems are considerably more succulent than others, and require wider spacing, in order to avoid molding.
Bob
I borrowed Bob's quote from another thread. I'm a first time grower. No doubt this question won't be needed after a season or two, but it would be nice to have some numbers for the first go-round if possible.
I get that if you are in New Mexico you probably need to add some moisture, and if you are in Panama you probably want the driest spot you can find. But I'm in western Oregon. Can I safely assume that R.H. of, say, 50% to 70% will provided a suitable environment for color curing in an unheated shed or outside in the shade? At what point should I move everything inside and maybe provide a little heat? Around 90% R.H.? Or does that oversimplify it?