Excellent points, colbaltdream!

I have two overlays on the skin, which obviously require separate materials. But I can combine things within those. I'll probably keep the lip zone, though, unless people convince me there ain't gonna be no revolution if I ditch it.

Thanks for correcting my anatomical mistakes regarding the eyes. What I called cornea is actually a transparent layer around the whole eyeball. On V4 this is called EyeSurface. I have no actual cornea at the moment, just two concentric balls with a slight dent at the front on the inner one for the iris and pupil, and a slight protrusion at the front on the outer one. I had a quick look at V3's and V4's eyes. I think they are quite similar to each other structurally, except for that extra layer on V4. I'm happy to take advice on how to rebuild the eyes if necessary. It's easy to do, and can make a huge difference in useability and realism.

You are right about the lashes. There's enough room to have left and right copies on one map, so I can use a single material.

Here's an alternative proposal on the material zones, assuming that I keep the eyes as they are. Call it the minimalist approach. :biggrin:

Map 1 (everything but the face and neck):
  01. SkinBody (includes skull)
  02. Nails

Map 2 (face and neck, including mouth, but not eyes):
  03. SkinFace (includes neck and eye sockets)
  04. Lacrimals (I forgot about those in my earlier post)
  05. Brows
  06. Lips
  07. MouthInner (includes gums and tongue)
  08. Teeth

Map 3 (eyeballs, left and right sharing one map):
  09. EyeWhiteLeft
  10. EyeWhiteRight
  11. IrisLeft
  12. IrisRight
  13. Pupils

Map 4 (transparent layers over eyeballs, ditto):
  14. EyeSurfaceLeft
  15. EyeSurfaceRight

Map 5 (lashes):
  16. Lashes

I've noticed that V4 has the material names prefixed with numbers. I presume those indicate texture overlays. Do people think that's a good practice? I thought it was quite nice to see at one glance what's supposed to be on the same map. Hopefully, they don't have a patent on that or anything. You never know. :biggrin:

BTW, I'm no specialist on Blender, but I believe the limit is 16 materials per object. I assume for most cases one could import the body and the brow, lashes and eyes as two or more objects, in which case my original proposal would still be within the limit.  That said, I'm more than happy to eliminate unnecessary material zones.

-- I'm not mad at you, just Westphalian.