Additive manufacturing involves making metal or plastic parts using technologies that precisely build an object by adding layer upon layer of material. "3D printing" is another term to describe this process. For many engineered components, additive manufacturing can't replace machining because the part produced this way still has to be machined to its final dimensions and tolerances. But additive processes do provide a way both to expand the range of forms that can be made easily and to get the part much closer to net shape before machining begins. At IMTS this year, additive manufacturing is an important focus of the Emerging Technology Center.