Aileen Chiu is a senior color engineer with Sun Chemical Corporation. As a member of the Global Color Management team, she supports colleagues around the world in various areas – from color science, printing workflow and calibrations, to data analysis and troubleshooting. She is involved in special projects such as SunMatch platform enhancement, ECG printing, and business improvement. Aileen has a BS degree in Graphic Arts from Chinese Culture University in Taiwan and two MS degrees from Rochester Institute of Technology: one in Graphic Arts Publishing and the other in Information Technology. With “printing” as the foundation of her career, enhanced by her knowledge in information technology, she has a strong focus in color reproduction and data analysis. She holds a patent for digitally printing color selection cards and is a certified G7 Professional and a Six Sigma Green Belt.

The Effect of Press Consistency on Brand Color Reproduction Using Extended Color Gamut Process Printing

Aileen Chiu, Sun Chemical

“Brand colors” are a key component to a brand’s visual identity. Traditionally, the brand colors are defined with spot colors. The printing inks are formulated accordingly across a variety of process and substrates – carton, film, and coated paper, etc. to produce the required brand colors on the packaging. A package design commonly contains three or four spot colors including the brand colors. Over time, not only the print manufacture accumulates leftover spot-color inks but also more waste was generated during make-ready and in the process of changing inks on press when dealing with multiple jobs that require various spot-color inks. With sustainability in mind, more and more printers are looking for ways to reduce waste and to optimize material management. The extended color gamut (ECG) process printing offers just the solution to achieve a sustainable production.

Conventionally, the process printing involves using cyan (C), magenta (M), yellow (Y), and black (K) inks for the image reproduction. The ECG printing is a print reproduction process that uses orange (O), green (G), and violet (V) inks in addition to the CMYK process inks. The three additional inks serve to extend the color gamut. The use of an ECG inkset to replace spot colors reduces in press wash-up time and spot color ink inventory and improves productivity with the options to gang up different brand color jobs.

Yet brand owners and printers have doubts: how accurate and consistent can the press hold the ECG process colors through the production run? With one spot color ink, the press operator only needs to control that one color. After the spot color is converted to ECG process color, the same design element comprises multiple process colors, which seems to introduce more variables. They suspect the separated color can fluctuate more easily on the press.

With a joint project between Sun Chemical and ESKO, a press trial was designed to investigate the following:
• How accurate can the predefined spot colors be reproduced in an ECG workflow including the color at the edge of the gamut?
• How consistent are the ECG colors from “within the sheet” and from “sheet-to-sheet” throughout the run?

An ECG press trial was conducted at Sonoco Institute, Clemson University, Clemson, SC, using Esko Equinox color management software and separations, in conjunction with Esko HD screening and XPS Crystal platesetter. Printing was done on the seven-unit OMET VaryFlex 530 flexographic mid-web press with UV LED flexo ECG process color inks and the coated paper label house stock.

With the selected screening system setting, plate, ink, and substrate, two press runs were conducted for calibration then for profiling. The third press run was prepared using the resulted profile to convert the special designed press form that contains spot colors into CMYKOGV process colors through ESKO Equinox system. The third run was kept at a production speed and for more than 50 minutes. Sample sheets were collected from the third run and much of the color data was collected and analyzed.

Based on the findings from the analysis result, it is concluded that for printers to implement ECG process printing for brand colors, the achievable colors can be reproduced in a consistent and accurate manner provided with a good and repeatable printing process condition and with proper calibration and profiling.

Ownership of data and paper: Sun Chemical, ESKO
Sponsorship: Sun Chemical, ESKO
Independent consultant for data analysis: Dr. Abhay Sharma
Press trial location: Sonoco Institute, Clemson University, Clemson, SC