Realmling covered the edges very well.  

Another important point has to do with holes or gaps.  Poser hates 
'concave' facets.  Many modeling apps leave very complicated facets,
including some concave facets, when you make a hole.

The hole will look fine in the modeler, and may be okay in
other rendering apps, but Poser will mess it up totally.

The solution isn't always easy.  Sometimes you can do it
by starting with a grid (checkerboard) as I did here; sometimes
you end up drawing the proper facets by hand!

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