To print a 3-D object, the manufacturer uses a 3-D computer-aided design (CAD) program to create a digital model that gets sliced into very thin cross-sections called layers. During the print process, the 3-D printer starts at the bottom of the design and builds up successive layers of material until the object is finished. 3D printers use a process called additive manufacturing to form (or "print") physical objects layer by layer until the model is complete. This is different than subtractive manufacturing, in which a machine reshapes or removes material from an existing mold. Since 3D printers create models from scratch, they are more efficient and produce less waste than subtractive manufacturing devices. The process of printing a 3D model varies depending on the material used to create the object. For example, when building a plastic model, a 3D printer may heat and fuse the layers of plastic together using a process called fused deposition modeling (FDM). When creating a metallic object, a 3D printer may use a process called direct metal laser sintering (DMLS). This method forms thins layers of metal from metallic powder using a high powered laser.
While 3D printing has been possible since the 1980s, it has been primarily used for large scale industrial purposes. However, in recent years, 3D printers have become much cheaper and are now available to the consumer market. As the technology becomes more widespread, 3D printers may become a viable means for people to create their own home products and replacement parts.
The creation of a 3-D object through an additive printing process. 3-D printing allows the small scale manufacturing of objects out of a variety of materials, including plastics and powders, through a variety of processes. The additive processes used vary according to materials used and budget, and may include laminates (laminated object manufacturing, LOM), resins (stereolithography, SLA), or melted materials (selective laser melting).