Press Performance Comparison between AM and FM Screening

FM screening has been praised for its apparent resolution advantage over conventional AM screening. FM screening is also known for its criticalness of film output and difficulties in the proofing stage because of the microdot formation. However, FM screening is not a well understood process from press performance point of view. This paper set out to explore (1) dot gain differences between AM and FM screening, (2) whether transfer curves, derived from AM and FM plate/press curves, can modify color-managed AM images for FM reproduction, and (3) how well does the dot gain compensation technique work in all parts of the color gamut. The IT8.7/3 basic color block, including 182 color patches, was used to test two FM screening methods, Agfa's CristalRaster and Ugra's Velvet. We learned that FM images can be successfully rendered to match closely to its color-managed AM reproduction when transfer curves are applied. This was verified by colorimetric analysis with the use of the IT8.7/3 target.