/RSR files are the thumbnails that show up in yr library in P4...they get created automatically when you save a figure/ prop/ pose/ etc in the Library (the pop out list @ the right). Pro Pack & P5 users don' need 'em, as those progs use .png thumbs which are smaller & widely supported by image viewin' sofware. If ya want to/ need to make custom .rsr thumbs, I believe P3DO Explorer (a free app) does that, as well as RSR Converter (also free....just search the FreeStuff section here)

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