Abstract: A subsystem for controlling the rheology of ink applied to an imaging surface of a variable data lithography system comprises an ink reservoir, an ink application subsystem for applying ink from the ink reservoir over the imaging surface at a first ink temperature, and an ink complex viscoelastic modulus control subsystem for modifying the complex viscoelastic modulus of the ink from a first value at the ink reservoir to a second value prior to transfer of the ink from the imaging surface to a substrate. The ink complex viscoelastic modulus control subsystem may comprise a partial curing stage, such as a photo-curing stage. The ink may optionally include photoinitiators to assist with the partial curing. Alternatively, the ink complex viscoelastic modulus control subsystem may consist of an ink pre-heating subsystem and/or a post-application cooling system.

Abstract: Methods for controlling the rheology of ink applied to an imaging surface of a variable data lithography system include applying ink in a layer with a first complex viscoelastic modulus such that said ink layer readily separates in regions over the imaging surface covered by a dampening solution and into regions over the imaging surface at which dampening solution has been removed, increasing the complex viscoelastic modulus of the ink to a second complex viscoelastic modulus while the ink is over the imaging surface, thereby increasing the level of at least one of ink cohesive energy and ink tack prior to the transfer of said ink to said substrate at said image transfer subsystem.