3D printing, also called additive manufacturing, refers to several technologies. By far the most common among consumer printers, however, is fused wire deposition. Concretely, the machine is powered by a coil of plastic wire that it heats to melt it. The melted plastic is then pushed through the printhead, which functions like a small pastry nozzle. The printer will then place the plastic on a tray in successive layers until the object is created.