Ink ceramic surfaces.

An ink composition for printing on a ceramic substrate, to be fused to the substrate after baking, the ink composition comprising - an aqueous dispersion of silica nanoparticles; and - at least one water-soluble inorganic additive selected r boric acid, sodium perborate, sodium tetraborate decahydrate, disodium octaborate tetrahydrate, aluminum phosphate and sodium silicate; wherein the ink has a viscosity below 20cps at jetting temperature of 30 to 60 measured by a Brookfield model DV-II + and becomes an integral part of the substrate when exposed to temperatures above 500 ° C.