Expanded gamut printing involves expanding the number of process colors by the three colors Orange, Green and Violet to create many spot colors with the new fixed CMYK-OGV ink set. The benefit of using expanded gamut printing is that the same inks can stay in the ink fountains of a printing press and only the printing plates need to be changed from job to job.
The authors conducted several studies with expanded gamut printing in digital printing, inkjet printing and offset printing. This study focuses on evaluating flexographic expanded gamut printing on a narrow web flexographic label press located at the School of Graphic Communications Management at Ryerson University, Toronto. Esko Equinox and GMG OpenColor expanded gamut software solutions were used, where each system was tested with its own proprietary characterization test chart. Idealliance ECG small v1 (2019) test target was also used in this study.
A verification test chart was created, with selected Pantone spot colors. The verification test chart was processed using the characterization data from the proprietary and nonproprietary characterization press runs. The build of the selected Pantone colors was analyzed and CIEDE2000 was calculated.
The main outcome from this study was that we conducted expanded gamut printing on a completely manual 7" narrow web label press and went through the step of optimization, curve calibration, characterization and verification. The average CIEDE2000 for the tested Pantone colors using the proprietary characterization charts was a CIEDE2000 of 2 and 3.2 with the Idealliance Small Chart. Both software solutions did better in regards to color accuracy with their proprietary characterization targets than using the data gathered from the Idealliance ECG small chart.