A photographic process that produces thicker or thinner images for color trapping in order to have easier registration in color printing is called spreads or chokes. A study was made of the conventional (contacting) method of producing spreads and chokes and the new technology by using orbital motion (Micro-modifier) with respect to the results on the films by measuring the printing sharpness, resolution, dot gain, base density, contrast, accuracy and uniformity of spreads and chokes. A cost study for both methods was also made. A series of experiments were designed and done in order to compare the two methods. The experiment's data were processed by the Regression Analysis Program of SPSS (Statistical Package for the Social Sciences). The results included three parts: ANOVA (Analysis of Variance), Prediction equations, and its graphical presentations. The results of this study indicated that the Micro-modifier method produced a better quality, higher accuracy and uniformity spreads and chokes compared to the standard method. In the long run, the cost of the Micro-modifier method is more economical. Therefore the Micromodifier method is highly recommended. Some of the Reliable Prediction Equations can be used for helping the strippers or cameramen to decide the correct exposure time, intensity, developing time and developing temperature to create a high quality , accurate and uniform spread or choke. This study indicates that the Micro-modifier method needs further study.
Library of Congress Subject Headings
Color printing; Color separation
Department, Program, or Center
School of Print Media (CIAS)
Lui, Sze-Men, "A study of the conventional method of producing spreads and chokes and the new technology by using orbital motion (micro-modifier)" (1981). Thesis. Rochester Institute of Technology. Accessed from
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