The resin blend technique is a simple and useful method for improving paint properties. It is more important for water-borne paints in which design of resins needs more sophisticated techniques. Combinations of special emulsions, microgels and water-soluble resins have yielded excellent aqueous binders for various coatings. The concept of resin blend in our research is based on (1) blending of resins to reinforce their advantages to each other and (2) blending of minor resin components to compensate for the major resin's weakness. This paper describes several specific examples of the resin blend for water-borne paints.