When you hear the word "printing," do you think of houses? How about cars? Drug doses? Solar panels? Most likely none of the above. And yet, all of these things are now being "printed." What began as 2D ink-on-paper 35 years ago has morphed into digital squirting, depositing, extruding, and rendering of all kinds of materials. Ultimately, printing is about software-controlled placement of materials on a scale stretching from atoms to autos to apartments.