Abstract

The purpose of this study is to determine if there is a proper press sequence for a specific set of process inks on a specified type of paper. In the past, the literature on this subject has been of a qualitative and generalized nature. This study attempts to put the matter on a quantative basis under strict controls. A standard set of process proofing inks for web offset are chosen to be printed onto a coated type of offset paper by an IGT Printability Tester. Various techniques are devised for printing solid strips of the inks with minimum density variation across each strip and from strip to strip. The density range of each ink is found by employing various techniques devised by the manufacturer of the IGT, and by using mathematical formulas. The density of each ink is plotted against its ink quantity, as read by each of three filters on a densitometer: Green, Yellow and Blue. The GATF formulas for determining the color characteristics of process inks are then employed. The results are tables for each ink showing the theoretical density of each filter reading at specified ink quantities, with the GATF Hue Error, Grayness and Efficiency factors included for those ink quantities. These tables allow for the predicted result of any overprints at specified ink quantities by adding the density of each filter reading at the desired ink quantity of each ink. In order to be as accurate as possible, a special technique is devised to read both single and overprint densities of ink films printed on the IGT. Overprints are made using an IGT Printability Tester, and a densitometer to compare actual to predicted values. Under controlled trapping, all conditions are kept constant, but the sequence is reversed. The sequence that comes the closest to the predicted values is the preferred sequence. This is found to be: Cyan, Magenta and Yellow. Although a preferred color sequence does exist for the set of inks used in this study, it is pointed out that a change in this sequence may help the overall result in certain cases.

Library of Congress Subject Headings

Printing ink--Testing

Publication Date

6-1-1975

Document Type

Thesis

Department, Program, or Center

School of Media Sciences (CIAS)

Advisor

Silver, J.L.

Advisor/Committee Member

Hacker, Robert

Advisor/Committee Member

Guldin, Mark

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: Z247.G5

Campus

RIT – Main Campus

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