The increasingly important and complicated technology of electrophotography (also called xerography), familiar to most people as the technology in photocopiers and laser printers, is the subject of this book, written for both the newcomer and the established expert. Introductory chapters acquaint the reader with the current status of electrophotography, including its technical history and current and projected markets. Alternative related copying and printing technologies are also presented. One chapter deals with the physics of the six process steps, with references giving access to the original literature. A further chapter points out the challenges of the development subsystem, which determines the best copy quality the customer can receive. Significant aspects of this system are not well understood and expensive manpower-intensive empirical design approaches are still required. The remainder of the book consists of a critical review of the literature of development physics, a thorough treatment of static electricity, and a discussion of two-component, monocomponent and liquid development systems. After mastering this material, the reader will have a working knowledge of the physics of the complete electrophotographic process and a detailed knowledge of what is known and not known about its most important subsystem, development.