Modern engineering often deals with customised design that requires easy, low-cost and rapid fabrication. Rapid prototyping (RP) is a popular technology that enables quick and easy fabrication of customised forms/objects directly from computer aided design (CAD) model. The needs for quick product development, decreased time to market, and highly customised and low quantity parts are driving the demand for RP technology. Rapid prototyping is a group of techniques used to quickly fabricate a scale model of a physical part or assembly using three-dimensional computer aided design data. Construction of the part or assembly is usually done using 3D printing or additive layer manufacturing technology. Until recently, prototypes had to be constructed by skilled model makers from 2D engineering drawings. This is a time-consuming and expensive process. With the advent of new layer manufacturing and CAD/CAM technologies, prototypes may now be rapidly produced from 3D computer models. There are many different rapid prototyping (RP) technologies available. This book delivers up-to-date information about RP technology focusing on the overview of the principles, functional requirements, design constraints etc. of specific technology.