Thesis - Open Access
Master of Science (MS)
Printing and Journalism
One of the biggest difficulties in the evaluation and control of high quality printed reproductions arises from the fact that no matter how carefully the halftones and tints are made, there is no assurance that their dot areas and densities will be faithfully reproduced on the printed sheet. Image size can be changed in platemaking, contacting or presswork. Assuming that the image or original dot areas get to the press unchanged by intermediate steps, there are still several variables which can affect the image areas on the press. The ink film thickness can either cause slur or spreading of small images such as fine lines and halftone dots. Excessive impression is a contributing factor in dot area changes which increase the ink spreading. The screen ruling of the halftone or tint will have an effect on the “clean running” capabilities of the press; and, an excessive ink-film thickness applied to the sheet may cause the excess in to be squeezed out into non-printing areas; this producing dot-area changes. Hence, it would seem that dot-area changes are more often the result of variations in component supplies, conditions and applications, rather than in the press itself. All of the above approaches, including their many individual characteristics, can be considered variables. These variables can be treated in one of three ways. First, they can be varied in a specific way, and therefore their effects can be estimated. Second, they can be held “constant” and their effects minimized; or third, they can be randomized to prevent their effects being interpreted as the effects of another variable. It should be noticed that constant is in quotations marks, for there is usually a minimum variation which cannot be eliminated by randomization. All of these treatments were used in this experimentation. (see more in text)
Library of Congress Subject Headings
South Dakota State University
Braswell, Jon Ralph, "An Experimental Investigation into the Effect of Density of Ink Film Thickness on Dot Area Changes on an Offset Press" (1968). Electronic Theses and Dissertations. 3418.