Details:
Summary:
Digital presses have become one of the most efficient ways to create short-run or personalized print products. Compared to traditional printing presses, it is also easier and quicker for digital presses to make changes in color management, especially with inline measurement systems. Inline color management can not only perform automated registration and real-time color density adjustments, but also create custom ICC profiles for different substrates under different environmental and press conditions. This inline process can be added into an automated workflow to ensure color matching or G7 conformance. However, it would be interesting to know whether the color measurement accuracy of the inline process using cameras is comparable to that of the offline process using spectrophotometers.
In this study, a Konica Minolta AccurioPress C2070 at Ball State University was used to compare inline and offline profiling processes. An inline IQ-501 Intelligent Quality Optimizer installed on the press along with EFI Fiery™ Color Profiler Suite was used to create custom profiles for eight paper substrates, three uncoated and five coated. The G7 method was used for calibration and then 1,617 patches (CGATS IT8.7/4) were printed and measured inline. The offline process was the same as the inline one except that an offline EFI ES-2000 spectrophotometer was used for color measurements. The inline process took about 5 - 10 minutes to create one profile, while the offline process took about 35 - 40 minutes, which confirmed that the inline process could greatly increase efficiency.
Profiles created using inline and offline processes were evaluated and compared in CHROMiX ColorThink™ Pro. It was found that the differences in gamut volume between profiles created by inline and offline processes were less than 1% for the three uncoated substrates, while the differences ranged from 0.66% to 4.58% for the five coated substrates.