INK JET PRINTING PROCESS

A process which comprises: a) incorporating into an ink jet printing apparatus: a color forming composition comprising a liquid vehicle and at least one color forming agent, and a reacting composition comprising a liquid vehicle and at least one material capable of reacting with the color forming agent to cause a desired color to form; b) causing droplets of the color forming composition to be ejected in an imagewise pattern onto the substrate; and c) causing droplets of the reacting composition to be ejected in an imagewise pattern onto the substrate; wherein the process results in at least some portions of the substrate bearing images comprising both the color forming composition and the reacting composition, said portions forming a printed image, wherein one of i) the color forming composition and ii) the reacting composition is applied to the substrate in fixed volumes per pixel, and the other of i) and ii) is applied to the substrate in varying volume per pixel, thereby varying the intensity of color of the printed image.