This study examines the effect of screening on dot gain and variability. Essentially two hypotheses are examined: first that as screen ruling is increased, the level of dot gain is increased; and second that as screen ruling is increased the level of variability is increased. These predictions are also applied to stochastic or frequency modulated screens which are presumed to behave as very screens due to their fine dot structure. A mathematical model referred to as the border zone is proposed to describe the nature of the gain and the variability for each of the screening systems. The hypotheses were tested by printing tint patches from a variety of screening systems (various screen rulings in addition to a FM screen) on a web press. The tint patches were then measured for gain characteristics. This data were statistically ana lyzed in relation to average gain and variability. The study determined that a correlation does exist between screen ruling and dot gain, but little evidence was developed to support the idea that screening relates to variability.
Library of Congress Subject Headings
Screen process printing
Department, Program, or Center
School of Print Media (CIAS)
Laughlin, Kelly, "An Investigation of amplitude & frequency modulated screening on dot gain and variability" (1994). Thesis. Rochester Institute of Technology. Accessed from
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