The Effect of Colorants in Proofing Systems in Comparison to Standard Four Color Process Inks

This study concerns the evaluation of the colorants of inkjet and laser proofing systems and their comparison to printed offset process colors.

Various types of proofing systems are being used today. In this study only inkjet ink and laser toner based systems were evaluated. These proofing systems use different colorants then pigment based offset printing inks. Due to the different chemical composition of inkjet inks and laser toners in comparison to the pigments used for printing on press, color differences are to be expected between printed sheet and proof.

The study intends to see how big the differences between 4 color process inks and randomly selected proofing systems are using color measurements with the CMC-tolerancing method. The prints will also be used to determine the obtainable color gamut of the evaluated systems. The gamut evaluation will also show if either system can reproduce colors that the other one can't.

Differences between the spectral curves of printing inks and the dyes can lead to metameric effects when proof and print are viewed under different lighting conditions (press-side and office lights).

The result of this study is that the cyan colorants showed the smallest color difference, while the magenta colorants showed the largest difference in comparison to the set standard. The smallest metameric index was observed with the cyan colorants. The yellow colorants gave the largest metameric index in this study.