3-D Printers Are Here -- and They Make More Than You Think

When we print something, a flat page comes to mind. For example, you might use a photocopier.
Photocopiers print in two dimensions.
Now, imagine how this would work for three dimensions. A machine prints layers of material -- usually plastic—one on top of the other. The layers are very thin -- usually one-fifth or one-tenth of a millimeter. The layers then combine to form a solid object.