In the 1914 H.G. Wells novel “The World Set Free”, Wells describes a uranium based continuously combusting explosive. Years later the remarkable similarities discovered between Wells’ fictional device and the atomic bombs invented and deployed during World War II were added to the ever growing list of instances where life imitates art. 3D printing had much the same backstory. In 1945 American author William Fitzgerald Jenkins published his short story “Things Pass By” under the nom de plume Murray Leinster. This story describes a machine that builds things, like houses and ships, using filaments that harden as they set. This is the first documentation of 3D printing as a concept. New developments didn’t occur until decades later. But first, what is 3D printing, and how does it work?