Thomas Rigg

Abstract

An investigation was made into one of the newer planographic printing plates, specifically 3M's Dry Plate. This plate is part of the system more popularly known as driography. As with many new processes, driography is beset with several problems. These include plate durability, substrate suitability, and toning. This study deals with the problem of toning and a. method for investigating it. In driography, toning is defined as the inking of the non-image background of the plate. Several factors are thought to have an effect on the amount of toning. Factors such as ink tack, ink temperature, room temperature, humidity, speed, and pressure are included. This investigation specifically researched the relationships between toning and ink tack, inking pressure, and printing speed. A parallel study of these relationships was made on both an IGT Printability Tester and on an ATF Chief 15 press. This was done in an attempt to show that the IGT Printability Tester could print driographically but, under the conditions used, it was a poor predictor of toning. Two methods of recording the effects of toning were used. One method was the recording of absolute densities taken in the non-image areas of the test sheets. The other method was the recording of a. ratio of the density of a solid patch to the density- of a tinted patch. It was hoped that the ratio would eliminate some of the extraneous variables that might affect the amount of toning. It was found, however, that the ratio result tended to record not only the pure toning, but also, the effects of some of the extraneous variables. Several statistical methods v/ere used to analyze the data accumulated. To compare one printing method with another and to compare one recording method with another, a correlation analysis was made and a graphical study done. To determine the reliability of the graphical analysis, a spot check was made using a paired comparison technique. An analysis of variance (ANOVA) was made of the data from each printing and recording method to determine the significant factors in the experiment. This experiment showed that ink tack, inking pressure, printing speed, and their interactions all were significant factors in toning. Unfortunately it was impossible to include some other factors in the experiment which are known to have a significant effect on toning. These include such factors as ink temperature, room temperature, and humidity. More work needs to be done in the area of driography, especially in toning. The crucial question is whether this is a plate or an ink problem. As more control is obtained over toning, the use of driography should increase.

Library of Congress Subject Headings

Offset printing; Printing plates

Publication Date

6-1-1974

Document Type

Thesis

Department, Program, or Center

School of Media Sciences (CIAS)

Advisor

Frazier, Clifton

Advisor/Committee Member

Hacker, Robert

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: Z252.5.O5 R5

Campus

RIT – Main Campus

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