Particulate or pigmented inks for thermal ink jet applications exhibit great print quality, far superior to dye based inks. In this paper, we present a concept for the development of smear-free pigmented inks by imparting polyurethane resin emulsions into ink jet inks. Inks are prepared by the addition of a polyurethane resin emulsion, and wherein the urethane groups can function as a crosslinking site with carboxyl or hydroxyl functionalities on carbon black colorant or other color pigment surfaces, thereby impart the ink smear resistance, film hardness, and humidity resistance. The addition of polyurethane resin emulsions also develops a list of attributes such as high optical density, good latency, excellent light- and waterfastness, superior black MFLEN, good frequency response, and excellent cool curl and showthrough properties.Polyurethane resin emulsions useful in ink jet applications are prepared by either processes: (1) polymerizing polyester polyol, polyisocyanate and acid in a solvent, followed by dispersing the mixture in water, or (2) an isocyanate terminated prepolymer is prepared in the melt or in an aprotic solvent, and is subsequently chain extended with a diamine in the water phase in the presence of a neutralizing tertiary amine.