Pigmented vitreous material its precursor glass items coated therewith and method of its preparation

The present application relates to a process for the manufacture of pigmented vitreous materials, as well as to pigmented vitreous materials, characterized by the use of soluble pigment precursors and preferably the absence of significant amounts of dispersants. These pigmented vitreous materials can be used as colored materials for any known purposes. Soluble pigment precursors comprising a partial structureare also claimed, wherein X1 is an aromatic or heteroaromatic ring, B is hydrogen or a group of the formulabut at least one group B is not hydrogen, and L is a solubilizing group.