We propose a new multilevel vector error diffusion method which introduces a control parameter S related to the physical amount of solvent (liquid) allowed for producing a given input color by combining dark (saturated) and light (unsaturated) ink separations. The solvent S appears as a fourth input variable to the error diffusion process where the quantizer is designed to choose the closest primitive in the CMYS space.
Serge Cattarinussi, Ana Dimitrijevic, "Multilevel Vector Error Diffusion with Solvent Control" in Proc. IS&T CGIV 2008/MCS'08 4th European Conf. on Colour in Graphics, Imaging, and Vision 10th Int'l Symp. on Multispectral Colour Science, 2008, pp 558 - 563, https://doi.org/10.2352/CGIV.2008.4.1.art00120