I believe MAC uses pict files. The easiest way to tell what your Poser is using is to go into the Pose library and look at what files are there. You will see .pz2 files and another type of file. The other type of file is your thumbnail. What a lot of people do is create .png files using a graphics program like PS or PSP then use the MacConverter to turn the thumbnails into MAC-happy files. Hope this helps, Cres