A word of warning, if I may, starting with some boring technical background. All versions of Poser from ProPack onwards can use any greyscale image as a bump map, where white denotes sticking out bits, and black is dented in bits. A good bump map is not just a desaturated version of the texture map - although that can form part of it - but a separate image which has been specially prepared to give the required effect. Poser 4 uses a proprietary image format (.BUM) which is based on BMP, but with information only in the red and green channels. I surmise this was done to make rendering faster, along the lines of the old .RSR geometry files. When Poser 4 is given a greyscale image as described above, it converts it into the .BUM format (and the Windows version of P4 does the conversion wrong, but that's another story). The .BUM format isn't just a simple translation; as the others have said, you can change a BUM file's extension to .BMP and read the file in any image viewer, but if you do that you'll readily see that it bears no relationship to the original image file. There was some discussion a while back on converting (or should that be reverting) .BUM files to greyscale images, but I can't find it now, and can't remember if a solution was found. But one thing is sure - although the methods described above will give you results, they won't be what the artist intended. Thanks for reading. Or, if you bailed out of my techno-rant halfway through, :P