Sharen - Welding then splitting then welding again inside UVM (as long as settings remain the same) just performs the same split/undo-split operation over and over. On the other hand, Poser can weld but does not have a corresponding split - so if you weld in Poser and want to split again, you must export to UVM (I know you know this, but for the sake of others it is here). When you export from Poser you will notice that the file size is LARGER with welded vertices than when imported from UVM with split vertices. This seems contrary to the notion that welding should reduce the vertex count and splitting should increase it (which are both true). But looking at the file size alone does not paint the full picture, because there is a lot more in an OBJ file than just vertex information. In this case, I believe the difference in file size is due to the fact that when you export from UVM, you do so without including normals (which we all know are ignored by Poser anyway). The funny thing is that when Poser exports an OBJ that had NO normals when imported, the normals are re-created and inserted into the file (as Vn lines) by Poser - therefore the larger file size due to the presence of normals. As far as I know there is no way to export from Poser without normals (as you can in UVM), so they are always added to the file even though Poser doesn't need them. For this reason, it is best to use the UVM exported OBJ rather than the Poser exported OBJ as the file that is placed in the Geometries library because the UVM version without normals will always be smaller than the Poser version. At least that's what seems to work best for me ;-)