The purpose of this study was to study the feasibility of quantitatively pre-setting the ink key distribution on an off-set press. Presently the pre-settings of the ink keys has been left to the pressmens' ability and experience. This, in many cases, involves much "trial and error" work along with lengthy makeready times. This study attempted to reduce makeready time by quantitatively pre-setting ink keys from data obtained from an estimating unit and use of a set of calibration curves. A photoelectric estimating unit was designed and constructed to read integrated densities of copy to be printed. There was one reading for each area of copy corresponding to an ink key on the press. The estimating unit consisted of a series of lenses, a photoelectric tube and a meter movement. The estimating unit yielded readings of the image area for which an ink key is responsible for the supply of ink. The press was a standard off-set type with small paper dials mounted on the face of each ink key. A series of calibration tints were printed. From these tints key settings and their estimated density values curves were generated for use in the pre-setting of the ink keys for any type of copy. Through one test it was found that there are many ways to have the ink keys set and still have the job within specifications. The reasons for this are explained within. Sample copy was read using the estimating unit. Through a series of steps predicted ink key settings were found. This copy was then printed using the ink key pre-settings. All press runs were evaluated to determine whether or not the pre-settings were producing printed copy within specifications. One hundred and ten possible ink key pre-settings were attempted. The results of the study show good correlation between pre-setting ink keys and actual settings done entirely empirically. With a quantitative method pre-setting the ink distribution keys, the makeready time required will be shorter.
Library of Congress Subject Headings
Offset printing; Printing; Printing ink
Department, Program, or Center
School of Media Sciences (CIAS)
Marino, Martin, "A quantitative method of pre-setting the ink distribution keys of an offset duplicator using a photoelectric estimating unit" (1976). Thesis. Rochester Institute of Technology. Accessed from
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