Printing without the use of a halftone screen pattern offers many advantages, although most processes utilized are impractical for long run commercial printing. Screenless lithography provides a practical means of making unscreened reproductions. While screenless lithography has been in use for many years, its working mechanisms have only recently been explained. Past studies have investigated many of the factors which contribute to the continuous tone effect of screenless printing, but none have scientifically determined if ink film thickness variation is a contributing factor. Positive working lithographic plates were exposed to control scales, processed, inked, and allowed to dry. These plates were then cross-sectioned and observed under a high magnification microscope to determine if variations in ink film thickness exist. Results showed that variations did indeed exist. These variations were shown to occur not only between areas of different density, but also within areas of uniform density. The different ink film thicknesses that exist on screenless lithographic plates affect their tone reproduction characteristics and contribute to their continuous tone capabilities.

Library of Congress Subject Headings

Printing plates; Lithography; Printing ink

Publication Date


Document Type


Department, Program, or Center

School of Media Sciences (CIAS)


Silver, Julius


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in December 2013.

Physical copy available from RIT's Wallace Library at Z247 .S85


RIT – Main Campus