Bald spots (head shape vs. hair shape)

Using the standard AV sliders, I am having just a heckuva time getting a tight head of hair without the AV's scalp breaking through.

Well 2 of my avs are either bald or partly, so that's fine. But on t'other, I'd like a nice short hairdo, along the lines of Russell Crowe's in "Master & Commander." I've got an OK texture, the problem is whenever I make the hair less than an afro-sized bush, some piece of the scalp sticks through...

Am I missing something, or is it just a matter of tweaking the head-shape and hair-shape sliders over & over?

Medlar.

I've had this happen with the few rare human avs I made sometimes.

Solution? I made a mostly-alpha tattoo for the head I can color in Photoshop that makes the scalp the same color as the hair.

Works pretty decent as long as no one is specifically staring at your head.