I did discover a rsr of 19MB for a 960kb obj That sort of thing happens when the same faces are in more than one group. In Poser's dialect of .OBJ language, e.g. the line g lForearm Arm Body_ means that the following faces are in group lForearm AND in group Arm AND in group Body_. When the .OBJ file is translated into .RSR mode, the faces involved are duplicated between all the groups that they are in.