“In many ways, the progression of 3-D printing from giant warehouses to living rooms has happened faster than anyone had a right to expect. 2-D printing was the exclusive province of industrial presses and foundries for centuries. Computers were refrigerator-size beasts for decades before the Commodore PET and the Apple II. And yet 3-D printers have gone from lab to living room in less than 20 years–and at prices that are already coming within reach of the upper-middle class.”