Do you need more grafts/cm² in areas where single hair grafts are used?

[alopeciaphobia]

I think most of us are very familiar with native density being ~85FUs/cm², and that ~60% of that native density (~50 FUs/cm²) being a very strong illusion of density (depending on other factors of course).

 

However, what really creates visual density are individual hairs, not FUs. So with 2.3 hairs/FU being average, ~200 hairs/cm² would be native density, and ~120 hairs/cm² would make a very strong illusion of density.

 

But what about the transition zone right behind the hairline (as described here, or here), where it's predominantly, but not exclusively singles? If you would place 50 grafts/cm² there, with say half of them being singles and half of them doubles, you would have 50 FUs/cm², but only 75 hairs/cm², which is actually pretty low density.

 

So I suppose my question is: in a non-balding person, is the area that's say, 1cm or 1/2" behind the hairline also ~85FUs/cm² and thus naturally much thinner in terms of hairs/cm², or is there naturally an increased amount of FUs/cm² to make up for the lower amount of hairs/FU?

 

From my experience, looking obsessively at hairlines of non-balding people, most (but not all) have just a millimeter or two of "softness", after which it becomes extremely dense already. Perhaps hair transplantation surgeons just make this transition zone much wider than it is natively to save grafts and blend it in better with a lower-density midscalp?

[Chrisno]

I have about 90-100 FUs natively, and was implanted at 85 FUs in my hairline. Singles first, then multis. The softness comes from the singles in the first few rows, that's the transition zone for a non-balding person.