This volume compiles a wealth of information on the composition, properties, utilization, and performance of major classes of additives while alerting formulators to potentially damaging interactions and challenges in the selection and testing of these materials. Completely revised and updated, the Handbook of Coatings Additives, Second Edition offers practical knowledge on the industry's most widely used compounds to accelerate and refine laboratory procedures, meet regulatory standards, and avoid hazards in the formulation of coatings additives. It is an ideal guide to making informed decisions in the development and design of effective coatings systems. Until recently, the coatings industry has relied mainly on organotin compounds for metal catalysis of NCO/OH reactions. With the development of new non-tin metal catalysts and with recent research of new and existing catalysts, it has become evident that catalyst selection is an important and complex issue that has become more complicated. These newly developed catalysts can provide new opportunities for managing old problems. This chapter is intended to provide a better understanding of the complexities of urethane catalysis and to develop guidelines for catalyst selection by troubleshooting commonly encountered problems.