FDM (fused deposition modeling) is a 3D printing process that uses a continuous filament of a thermoplastic material. Filament is fed from a large coil through a moving, heated printer extruder head, and is deposited on the growing work. The print head is moved under computer control to define the printed shape. FDM is now the most popular process (by number of machines) for hobbyist-grade 3D printing. Other techniques such as SLA and SLS may offer better results, but they are much more costly.

Stereolithography, many times referred to as SLA, uses a laser to solidify a photopolymer resin building parts layer by layer. Stereolithography (SLA) is a great choice for complex prototype geometries because of the precision to which it builds and the ability to apply a multitude of finishes. Stereolithography (SLA) is defined as Vat Polymerization and is one of the seven processes defined by ASTM F42. SLA can be used to create things such as prototypes for products in development, medical models, and computer hardware, as well as in many other applications.

Selective laser sintering (SLS) is an additive manufacturing (AM) technique that uses a laser as the power source to sinter powdered material (typically nylon/polyamide[1][2]), aiming the laser automatically at points in space defined by a 3D model, binding the material together to create a solid structure. It is similar to direct metal laser sintering (DMLS); the two are instantiations of the same concept but differ in technical details. Selective laser melting (SLM) uses a comparable concept, but in SLM the material is fully melted rather than sintered,[3] allowing different properties (crystal structure, porosity, and so on). SLS (as well as the other mentioned AM techniques) is a relatively new technology that so far has mainly been used for rapid prototyping and for low-volume production of component parts. Production roles are expanding as the commercialization of AM technology improves.