Just put whatever texture you want on as the "preview" material. It doesn't mean it's preview only, just that it's the generic name for it :o) If you want other materials (or want to give it another name) open the Grouping tool, select the polygons you want to rename and hit the Assign Texture (or whatever haven't got Poser opened right now) - then exit grouping tool again, save the new prop to the palette and you're all set :o)

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.