I haven't tried to 'convert BUM back to JPG' but found that PSP will open many but not all BUM files. As for making 'your own BUM'....sounds like something for me to playwith this weekend (Tues, Wed for me) but I do definatley prefer to set up my own Gray Scales for Poser to make BUMs rather than just converting the actual 'texture' JPG. Lots more control and effects with better definations can be achived.