Measurement of Ink Film Thicknesses Printed by the Litho Process

A method for measuring ink film thickness on paper is described. Four conditions which must be satisfied to achieve acceptable results are identified and discussed. The validity and usefulness of the method are demonstrated with data obtained in more than forty-five measurements, made over the past none years. These consist of nine measurements on a newspaper press, five on a heat set press, and over thirty on two different sheetfed presses. Data presented include numerous plots of print density versus ink film thickness and comparisons showing the extent to which the water used in the lithographic process affects print density and ink lay.