Patent ID: 8603233

Claim:
An ink set for digital printing comprising: a liquid colouring composition (A) selected between i) a composition consisting of a solvent and one or more cobalt compounds, and ii) a composition consisting of a solvent, one or more cobalt compounds and one or more salts and/or complexes of chromophoric metals chosen among Bi, Ce, Cr, Cu, Mn, Ni, Pr, Sn, Ti, V, Zn, Zr, Al; a liquid colouring composition (B) selected between i) a composition consisting of a solvent and one or more iron compounds, and ii) a composition consisting of a solvent, one or more iron compounds and one or more salts and/or complexes of chromophoric metals chosen among Co, Ni, Cr, Mn, Ti, Zn, Zr, Sb, V, Pd; a liquid colouring composition (C) selected between i) a composition consisting of a solvent and one or more compounds of chromium, one or more compounds of nickel and mixtures thereof, and ii) a composition consisting of a solvent, one or more compounds of chromium, one or more compounds of nickel, and at least a compound of a metal chosen among Sb, W, Ti, Ce, Fe, Mo, Ni, Sn, V, Zn, Zr and mixtures thereof; and at least one between a liquid colouring composition (D) and a liquid colouring composition (E), wherein said liquid colouring composition (D) is selected between i) a composition consisting of a solvent, one or more cobalt compounds and one or more iron compounds, and ii) a composition consisting of a solvent, one or more cobalt compounds, one or more iron compounds and one or more chromophoric metals chosen among Bi, Cr, Ce, Cu, Mn, Ni, Pr, Sn, Ti, V, Zn, Zr, and said liquid colouring composition (E) comprises a solvent and one or more zirconium compounds, in which said metal compounds decompose by heating to temperatures between 500 and 1300° C. the metal compounds of compositions (A) to (D) forming the respective coloured oxides or coloured compounds derived from the interaction between the metal and the ceramic material onto which said ink set is applied, and the zirconium compounds of composition (E) forming white oxides or white compounds derived from the interaction between zirconium and the ceramic material onto which said ink set is applied.