An Engineer's Analysis of the Lithographic Printing Process.

A model which explains the unique features of the lithographic printing process is postulated. In the source of developing this model, the main elements of a lithographic printing press are reviewed, with special emphasis being paid to the inking and damping systems and the actual film thicknesses they apply to the printing plate. Material properties of significance to lithography are identified and typical values for materials used in practice are presented. The various conditions encountered in roller nibs are categorized and nip behavior is summarized in a truth table-type of presentation. Following its establishment, the model is tested by using it to explain so-called conventional lithography, in which a damping system applies fountain solution to the plate in an operation separate from, and preceding, plate inking. The model is then used to describe ink-feed dampening, as best exemplified by the DAHLGREN system. Additional variations of lithography, along with other process phenomena are also discussed in terms of the model.