Evaluation of the Color of Printing Inks.

The widespread use of the Preucil system of ink evaluation, based on densitometer measurements through color-separation filters, has been criticized since the spectral sensitivities do not correspond to visual color-mixture curves and are not standardized. The reasons for the success of this system, which offers several advantages over conventional colorimetric systems, not only for establishing proper color correction but also for representing the approximate gamut of colors covered by a set of inks, are discussed. Two new colorimetric parameters (strength and inefficiency) are proposed, which offer many of the advantages of the Preucil system but are based on colorimetric measurements. The strength represents a combination of Munsell value and chroma, and the inefficiency indicates how far the color is from the corresponding color of theoretical maximum efficiency. Munsell hue is used as a third parameter. A so-called ideal ink would have zero inefficiency in this system.