Details:
Summary:
Since the recent revision of ISO 12647-2 and ISO 12647-7, specifiying the requirements for systems that are used to produce hard-copy digital proof prints, the use of color measurement instruments are more required in the printing industry. Currently, there are many different models of color measurement instruments used in the printing industry. Therefore, in a modern color managed workflow, most of the printing houses use more than one color measurement instrument, typically one instrument in each department (prepress, press, and post-press). In this paper, a total of nine spectrophotometers are compared in terms of precision, accuracy and reproducibility. The BCRA series 2 ceramic gloss tiles from the BCRA series are used to confirm the accuracy and repeatability of these measuring instruments according to the manufacturer's standards. Factors contributing to the measurement errors, in the colorimetric measurements by using more than one color measurement instrument in the printing workflow (from prepress to press and post-press) are studied using these 9 spectrophotometers. For this, four different materials are used, one proof print, one commercial print, and one reference print, along with the BCRA series 2 ceramic gloss tiles. Since the ISO standards have defined tolerances for the solids of the process colors, the accuracy of the color measurements are determined on these. The impact of the colorimetric measurement errors in the production workflow due to large inter-instrument variability between different measuring instruments used in the workflow (instrument in the printing house, and the instruments used at the customer's site for inspection and certification) is demonstrated in this paper.