Book excerpt: Rapid prototyping is an exciting new technology used to create physical models and functional prototypes directly from CAD models. Rapid tooling concerns the production of tooling using parts manufactured by rapid prototyping. The book describes the characteristics and capabilities of the main known rapid prototyping processes. It covers in detail various commercially available processes such as: Stereolithography (SLA), Selective Laser Sintering (SLS), and others. The text places a strong emphasis on practical applications and contains an abundance of photographs and diagrams to illustrate clearly the principles of the machines and processes involved.