3D printing is a manufacturing process in which material is laid down, layer by layer, to form a three-dimensional object. 3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model.

It can be done in a variety of processes in which material is deposited, joined or solidified under computer control, with material being added together, typically layer by layer. In an additive process an object is created by laying down successive layers of material until the object is created.