forming an imagewise pattern of a diazo dye on a substrate, said dye comprising the reaction product of an aromatic coupling agent with a diazonium salt comprising: wherein R is hydrogen or an alkyl, Y is a halogen and X is an anion selected from the group consisting of: halogens, NO3 ???, HSO4 ???, BF4 ???, and PF6 ???; and wherein said aromatic coupling agent is selected from the group consistin