THE AUTHOR COLLABORATED WITH RONALD Bauer and Edward Marx in preparing this chapter for the previous or 14th edition of this manual. This revised edition includes expanded descriptions of epoxy materials and curing agents currently used in coating formulations. Epoxy resins are versatile materials that are used in a wide variety of coatings. In the interests of brevity, this chapter focuses on the epoxy resins, curing agents, and coating types that are commercially most important and account for the largest usage of epoxy resins. As an example, epoxy coating technologies, which reduce volatile organic compound (VOC) emissions, have grown rapidly. Waterborne, high solids, and powder epoxy coatings account for about 80 % of all epoxy resin used in coatings. On the other hand, low solids epoxy coatings have declined significantly in importance and account for less than 15 % of epoxy resin usage. So this chapter naturally focuses on the low VOC technologies. Similarly, epoxy ester coatings were described in the previous edition, but have declined in importance, so they are not discussed here. Also, epoxy coatings are formulated with other materials described in this manual, and attempts have been made to reference those chapters where appropriate.