3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file. 3D printing is achieved using additive processes, where an object is created by laying down successive layers of material. 3D printing is considered distinct from traditional machining techniques (subtractive processes) which mostly rely on the removal of material by drilling, cutting etc.

3D printing is usually performed using a materials printer, and since 2003 there has been large growth in the sales of these machines. Additionally, the cost of 3D printers has gone down. The technology also finds use in the fields of jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many others.

Additive manufacturing (AM) also known as 3D printing is defined by ASTM as the "process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies, such as traditional machining. Synonyms include additive fabrication, additive processes, additive techniques, additive layer manufacturing, layer manufacturing and freeform fabrication".