Dot gain is the increase in size of a halftone dot or array of dots that takes place in the stages of reproduction of an image from original film to printing on a substrate. Uncontrolled dot gain is a source of multiple print quality problems including color variation, loss of detail and high waste factors during printing. Several factors have been identified as causes of dot gain. One factor that had not been investigated was the effect of press operating speed on dot gain. The purpose of this investigation is to study the effect that press speed has on dot gain. The experiment was designed to test the hypothesis that dot gain decreases as the operating speed of the press is increased. Experimentation was performed on Rochester Institute of Technology's Harris M-1000B web press. The press was operated at four different speeds. Measurements of ink density were recorded from the sample press sheets collected during the experiment. The density measurements were analyzed and converted to dot area for comparison. Statistical analysis of the data collected affirmed an inverse relationship between press speed and dot gain.
Library of Congress Subject Headings
Offset lithography; Photoengraving -- Halftone process; Printing -- Quality control
Department, Program, or Center
School of Print Media (CIAS)
Mudge, James B., "A Study of the effect of lithographic press speed on dot gain" (1991). Thesis. Rochester Institute of Technology. Accessed from
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