The Comparison of Print Quality between EPM and CMYK of Digital Offset Printing Systems LEP

Abstract

The purpose of this research is to compare the print quality between EPM and CMYK of digital offset Liquid Electrophotography (LEP). First, the TC 3.5 CMYK i1 profiler test chart and Test Form of Altona Test Suite version 1.2 in EPM mode and CMYK mode were printed with HP Indigo 12000 printer. After that, the print qualities of the test form were measured and evaluated with a questionnaire by the specialists. The research result was found that the EPM printing produced colors closed to CMYK printing in highlight areas. Printing with CMYK mode had wider color gamut in shadow areas and printing with EPM mode had wider color gamut in highlight areas. The evaluations from the specialists showed that the CMYK printing was better on the images of portrait skin tones, portrait grayscale, duo tone, low key, animals, material skin, saturated colors and graphics because the images of CMYK printing were intensity, sharp and realistic. The images of EPM printing satisfied by the specialists were high key, wedding, fabric resolution and foods. Therefore, The EPM printing is suitable for printing the images that could show moiré and high key.