Additive manufacturing is a process of making a three-dimensional solid object of virtually any shape from a digital model. Additive manufacturing is achieved using an additive process, where successive layers of material are laid down in different shapes. Additive manufacturing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes). The first working additive manufacturing process was created in 1984 by Chuck Hull of 3D Systems Corp. Since the start of the 21st century there has been a large growth in the sales of these machines, and their price has dropped substantially. Additive manufacturing technology is used for both prototyping and distributed manufacturing with applications in automotive, aerospace, military, engineering, dental, medical, fashion, footwear, jewelry, eyewear, architecture, construction (AEC), industrial design, education, geographic information systems, food, and many other fields.