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I see a bit of a hard edge on the right nipple. I'm wondering if there's a little bit of angle change built into the geometry that is causing that? I don't think it's the mask - it seems pretty smooth. I'll have to try just rendering with a simpler shader so I can see what's going on there.

Yep, it's an angle change. Poser makes a hard edge there because of those 's 1' and 's 2' lines I mistakenly left in the file. They are called smoothing groups. Each polygon belongs to either group 1 or 2 (in case of Antonia; there could of course be more than two groups). Poser does not average normals between polygons that belong to different groups, which is why you see a sharp angle there.

If you take all the lines starting with 's' out, there's only one default smoothing groups and everything should look nice.

The reason I have an hard edge there is so that the outline of the areola doesn't move when I subdivide from my original low-poly mesh. I should have removed them from the subdivided mesh, but I forgot.

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