Like many technological advances that make the headlines, the technique of 3D printing, or additive fabrication as it is more properly called, is not really new. industrial manufacturers have been using it for decades, primarily as a quick way of creating prototypes. What is new, however, is that 3D printers have become inexpensive enough to be readily available to the average person. Nowadays you can get a 3D printer for US$1,000 – although you will still pay a... (GunPolicy.org)