In FDM, the resin is liquefied and pressed through fine nozzles, producing a thin thread that deposits the individual object layers, one at a time. As FDM is based on the principle of additive manufacturing, a second resin is processed simultaneously. This second resin serves to build support structures for the model and is removed upon completion. Typically, ABS models are monochrome and can be made in black, white or any elementary color.