It's nice to export a Figure out as a .PNG, because you do'nt need an Alpha for any Photoshop Channels palette; but there are limits to Composition.  What's great is you can just export a Figure, with hair clothes etc., and have everything else around it be Transparent Pixels when Opened in Photoshop; but the transparent pixels are only generated by Poser's Background.  For example if the Background of the scene is an Image(you loaded File > Import > Background...etc.(Or even the Background is just one color) then you are all set; but if there is a house Prop behind the Figure, or even another Figure then the contiguous 2D parimeter of the Figure's encompassesment by Transparent pixels would be compromised.

Alternatively, turn the Background Color/Image Black.  Go to the Materials Room, and set a Part to %1000 White; then set all of the other PoserSurface noes, in the Figure, to the one changed.  Render...

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