WATER-BASE INK, INK SET AND METHOD OF IMAGE FORMATION Russian patent published in 2009 - IPC C09D11/00 B41J2/01 B41M5/00 

FIELD: printing industry.

SUBSTANCE: ink set of four water-base ink types includes cyan, magenta, yellow and black ink in which each ink contains water, water-insoluble dye and several water-soluble organic solvents that are favourable environment or favourable environments for water-insoluble dye and unfavourable environment or unfavourable environments for water-insoluble dye and in that: relation B/A for each ink colour amounts to from 0.5% or more to 3.0% or less where A stands for favourable environment total content (wt %) of cyan ink total weight and B stands for unfavourable environment total content (wt %) of cyan ink total weight and water-soluble solvent which reveals maximal Ka value among respective Ka values for several water-soluble organic solvents defined by Bristow method and is unfavourable environment.

EFFECT: high degree of surface covering even with small amount of ink drops, possibility of forming high density image, increased stability during storage.

15 cl, 13 dwg, 12 tbl