Date of Award

5-2008

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Career and Technical Education

Advisor

Ingram, Sam T

Committee Member

Poston , Cheryl

Committee Member

Hill , Hoke

Committee Member

O'Hara , Liam

Committee Member

Woolbright , Nona

Abstract

The Near Neutral Calibration Process was conducted on three different printing processes. They ware the flexo direct-print corrugated press (Bobst 160), the flexo narrow-web press (Comco Captain), and the commercial sheetfed offset lithographic press (Heidelberg Speedmaster CD102). The E-flute Kemiart Lite liner corrugated board was used for the Bobst, the gloss label substrate was used for the Comco, and the gloss text paper was used for the Heidelberg. The ISO 2846-5 ink sets were both donated from Color Resolutions Internationals for two flexo printing processes. An ISO 2846-1 ink set from Toyo was used for sheetfed offset lithographic process. The print attributes, color attributes and visual comparison were compared among these three different printing processes. The print attributes included chroma of the mid-tone three-color neutral gray, mid-tone three-color neutral print density, solid ink density, print contrast, 50% tone value increase, and trapping. The color attributes included color difference and color gamut. The visual comparison was conducted using two ISO SCID images under the standard D50 light booth. This study found that there were statistically significant differences for most of the print attributes among three printing processes. The Bobst 160 had a smaller color gamut than that of the other two printing processes. However, there was no statistically significant mean color difference value between the Bobst 160 and the Comco Captain, between the Bobst 160 and the Heidelberg Speedmaster CD102, and between the Comco Captain and the Heidelberg Speedmaster CD102. The average ΔE2000 color difference values were less than 4. In addition, more than half of 30 participants answered that 'yes, they would accept the visual differences among three prints'. As a result, by implementing the custom Near Neutral Calibration Process to calibrate three different printing processes to achieve neutral at 50C40M40Y gray, the color difference can be reduced significantly while the print attributes and color gamut were significantly different.

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