I use that method too when I am just making one or two thumbnails, but when I want to add special text to them or make a lot of thumbs from scratch, there is a way to do it in an image editor. I use photoimpact, but I think this will apply to PSP and Photoshop as well. The PNG that Poser uses requires a transparent background and a single layer. All you have to do is set your background to transparent and create a new layer to hold whatever visual information you want. When you save the PNG be sure that "preserve transparent background" option (or whatever it is called in your program) is enabled - similar to the way you save a GIF with transparent background.