Thirty years have passed since 3-D printers first appeared, but only recently have they hinted at a new era of manufacturing. The first working 3-D printer was created in 1984 by Chuck Hull of 3D Systems Corp. This early device, based on stereolithography, gave way to the first truly practical 3-D printing technology patented by the Massachusetts Institute of Technology in 1993. Since the start of the 21st century, there has been a large growth in sales of these machines as their prices dropped substantially. Today, 3-D printers have become more of a staple in the current manufacturing space, while still piquing hobbyist interest. The 3-D printing process usually works by selectively binding powder particles together, layer-by-layer, using a high-resolution inkjet printhead. A thin layer of powder is spread across the build area specified by CAD software, creating layers.