To anyone who hasn't seen it demonstrated, 3-D printing sounds futuristic-like the meals that materialized in the Jetsons' oven at the touch of a keypad. But the technology is quite straightforward: It is a small evolutionary step from spraying toner on paper to putting down layers of something more substantial (such as plastic resin) until the layers add up to an object.

this link can help for 3D printing for geopolitical impact