Disclosed is a process which comprises (a) incorporating into an ink jet printing apparatus (1) a first ink comprising water and at least one anionic monomer; and (2) a second ink comprising water and at least one cationic monomer, wherein the anionic monomer and the cationic monomer are selected so that upon contact of the anionic monomer with the cationic monomer, spontaneous polymerization or copolymerization of at least one of the anionic monomer or the cationic monomer occurs, and wherein at least one of the first ink and the second ink further comprises a colorant; (b) causing droplets of the first ink to be ejected in an imagewise pattern onto the substrate; and (c) causing droplets of the second ink to be ejected in an imagewise pattern onto the substrate; wherein the process results in at least some portions of the substrate bearing images formed from both the first ink and the second ink, said portions forming a printed image containing the colorant and a polymer formed from at least one of the anionic monomer or the cationic monomer. Similar processes are disclosed with N,N-dimethylaminoethyl methacrylate and p-toluene sulfonic acid, with acrylamide and a multivalent metal nitrate salt, and with 5-vinyl tetrazole and an amine base.