Daddy brought home a 3-D printer to stay with us for a few days, ah, the joys of living in the Bay Area with a daddy who has free access to toys and the latest technological gadgets! He actually did want to run it and see if it was working properly and thought the boys would enjoy seeing it in action (he was right). So, in short, 3-D printers layer on very hot plastic from a computer model/design, going back and forth like a typewriter so the object is built in layers and pretty slowly. John out in a design for a small globe, and after you clean off the list toe bits and pieces of excess plastic, it looks pretty good. It isn’t heavy plastic like the ABS plastic that Legos are made of, but it isn’t flimsy plastic either. Luke enjoyed watching it, and seeing how you input the designs, but he is my tinkerer/builder guy, so that isn’t a shock.