Phantast: "But surely both Propack and P5 can READ .rsrs? So if everyone defaults to using .rsr than everyone will be OK." True, except for one gotcha. The first time Pro-Pack finds the .rsr thumbnail, it creates a .png thumbnail, and from that point on, it never looks at the .rsr file again. Normally, this is fine. But if you ship a product, then later have an update that changes the thumbnails, Pro-Pack users won't see the updates. That's why we ship both .rsr and .png thumbnails. ( And we have needed to update thumbnails...we had some floor textures where the thumbnails showed the whole floor, and they were too small to see the pattern. In the update, we zoomed in on the pattern.) Many vendors may never have the need to update thumbnails, so just shipping .rsr files will work fine with them. Since we have needed to in the past, we always ship both formats. (By the way, you could actually get by with just shipping .rsr files, and then shipping both when you do the first update.) (By the way, a similar problem exists with Poser 4 (non Pro-Pack) and geometry .rsr files. The first time Poser 4 uses a .obj file, it creates a geometry .rsr file, and doesn't look at the .obj file any more. To update a product's .obj files, you also have to ship geometry .rsr files, or the non Pro-Pack users won't see the updates.) Rawnrr: You can't just rename the .rsr files. The format is quite different. Actually, the .rsr files are the same as the Mac PICT (.pct) files, with a header and trailer slapped on the front and back. Lynn Grant Castle Development Group