Abstract

Screening is used to convert continuous tones images in printing dots. Printing is done by transferring these dots to the desired substrate under defined printing conditions. The aim of this research is to identify the significant dot gain differences of Hybrid Modulated (XM) & Digitally Modulated (DM) Screening on different grades of paper printed by offset printing process. The experiment is conducted using FOGRA 39/ PSO standard. This research work is based on an experiment. To conduct this research work, the master of 44.5×29.5 cm output is prepared by incorporating quality measuring parameters and printed in KCMY colour sequence on different grades of paper on RYOBI 524HX (Sheet fed Offset) by using XM and DM screening technologies. During printing, around 150 sheets are printed to achieve target Solid Ink Density value (+ 0.05). After the density values are attained in accordance with standard SID values, another 50 sheets are printed for spectrophotometer analysis. Solid Ink Density patches are not compared here because both screening technologies are likely to produce identical results.

Key Words: Hybrid Modulated Screening (XMS), Digitally Modulated Screening (DMS), Dot Gain, Trapping, Print Contrast