Selective laser sintering is a form of 3D printing in which flat layers of a 3D model are built up by welding together metal powder to form each layer. Once a slice has been formed, a new layer of powered is set on top and the process repeats. Eventually, these slices of welded metal form the 3D model, with the unused powder acting as a sort of passive structural material for the 3D form. This re-imagining of the technology- intended for medical engineering applications- uses high powered, pulsing electron beams to weld together layers of titanium powder.