Ink compositions and multicolor thermal ink jet printing process for the production of high quality images

A multicolor ink jet printing process which comprises:

• (a) incorporating into an ink jet printer a first ink having a first color and comprising water and a colorant selected from the group consisting of (1) anionic dyes, (2) dyes having physically or chemically associated therewith a stabilizing agent having anionic groups thereon, (3) pigment particles having anionic groups chemically attached thereto, (4) pigment particles having physically or chemically associated therewith a stabilizing agent having anionic groups thereon, and (5) mixtures thereof;
• (b) incorporating into the ink jet printer a second ink comprising water, an optional colorant having a color other than the first color, and an ammonium salt having at least two cationic ammonium functional groups;
• (c) causing droplets of the first ink to be ejected in an imagewise pattern onto a substrate;
• and (d) causing droplets of the second ink to be ejected in an imagewise pattern onto the substrate, wherein the colorant in the first ink is immobilized on the substrate by interaction with the ammonium salt having at least two cationic ammonium functional groups in the second ink, thereby enabling reduced intercolor bleed.