heyas; open the dress, and position the lights and camera to take a nice 'snapshot' of it. turn on texture preview mode if you want to see the textures. if it has transparency, or if you want more details you can also render it and paste it to the background. (if you do THAT, then you should move the camera so that the actual model of the dress/item isnt in the view any more.) save the item back to the library. if the library rsr is not write-protected, it should generate a new thumbnail for you. even in pro pack, if i'm not mistaken, saving the item to the library should create a new png thumbnail. its really not as difficult as all that you're trying to do. ;)