Identification of Coloring Agents Causing Poor Coloring Reproducibility in Computerized Color Matching

Two methods are used for color matching: visual color matching and CCM(computerized color matching) which is now used quite frequently. Although CCM decrease the color difference more easily, color correction must be repeated in the case of unstable color development due to the limited coloring reproducibility. There is no CCM system to display coloring reproducibility. A previous report described how coloring reproducibility can be displayed by using the spectral differences between the measured and CCM simulated spectral reflectance of color matching samples. The main point of the study reported here is identification of the coloring agents causing poor coloring reproducibility. It is especially important to identify the achromatic coloring agent. It become possible by the following methods. The spectral defference between the measured and simulated spectral reflectance of the abnormal color matching sample includes the abnormal component and the original simulation error. The quantity of the colorants of the abnormal sample is calculated by means of offsetting the original simulation error. The colorants causing abnormalities can be identified based upon the changing ratio of each colorant versus the recipes of the colorants originally planned to manufacture.