But Poser 4 PRO PACK also uses png's. So that shouldn't be the problen... Anyway, to convert png's to rsr's you'll need Yarps P3DOExplorer. I think it's here in Free Stuff.

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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.