Graeme, > To go any further in understanding how it works, you would need > to compile the gamut/gammap.c code with PLOT_GAMVEC and PLOT_GAMUTS > #defined, and examine the resulting VRML plots for typical > RGB to CMYK links using perceptual and saturation. Thanks Graeme. I've done this, and I'm not 100% sure whether the sRGB source is really being mapped all the way out to the extent of my printer's gamut. FWIW, I've dumped all the files here if you or anyone else is interested: http://www.sullivang.net/color_stuff/ Greg.