Book excerpt: Aqueous polymer dispersions are environmentally friendly and therefore they have replaced in many applications polymers dissolved in organic solvents. This substitution process is still ongoing. This book discusses the world of aqueous polymer dispersions from the viewpoint of how they are applied. For a better understanding it starts with a general description of the synthesis of polymer dispersions and their characterization. The following chapters are dedicated to a wide variety of applications, including history, modern processes, and typical formulations and performance. The selection and the usage of a polymer dispersion are not uniform around the world because of historical and regional differences of the technical developments and marketing demands. Leading scientists from industry contributed to this book ensuring that practical issues are emphasized.