The metameric mismatch gamuts are calculated and plotted for a number of colorant and substrate types, including nylon and polyester textiles. Four illuminants were used in this study; D65 (representing daylight), source A (representing incandescent light), and two fluorescent lamps (lamp types F2 and F11). The choice of reference illuminant was found to affect the size of the mismatch gamut for a given test illuminant. Mismatches were smallest when the reference illuminant was D65 and largest when source A was used for the initial matching. These findings imply that the use of daylight for retouching is a sensible choice if metamerism is to be minimized. -- AATA