A 3D object is created by wastefully removing bits of material from a 
larger block, 3D printing works by building an object layer-by-layer and
 only adding the necessary material to create the object. The process of
 additive manufacturing is to first develop a model, which is then 
digitally produced and sliced into thin layers. The printer adds plastic
 layers on top of each other through precise motions until the print is 
complete.