For building camera profiles, I primarily use targets created with Argyll on an Epson 9900 printer. So the target patches are constructed from just 7 pigmented colors plus 3 levels of black. I measure them with Eye-One Pro Rev D in high resolution mode. It seems like there must be some degree of metameric failure going on when I'm using these camera profiles to capture images from a wide variety of sources: watercolors, colored pencil, pastels, photographic papers, acryllic paint, lithographic prints, oil paint, etc. What tools and techniques would help me gain a better understanding of any metameric mismatch that is happening? I'd love to be able to predict it and quantify it. I'm not sure where to start. Thanks. - Brad