The term "3D Printing," though, is itself potentially questionable. On appearance the technology resembles plotting machines more than printers (in the traditional sense of the word). Originally, the method was called "additive manufacturing" and defined as "the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies." This means that objects are formed from applying directed material from start to finish as opposed to using an already existing material form and creating a shape by removing from it. The first method of additive manufacturing was invented in 1984 (patented in 1986) by Charles Hull and called "Stereolithography," using ultraviolet light onto liquid photocurable resin (here is a retrotastic short video demonstration). Charles also invented the standard 3D Printing CAD file format STL. Other methods from the 80s include "Fused Deposition Modeling" by Scott Crump, which constructs forms using a controlled jet of filament (the method we are all most familiar with today) and "Selective Laser Sintering" which is similar to Stereolithography in practice but can produce forms in many other materials. Onwards into the 90s, more methods were introduced and businesses specializing in this manufacturing technology emerged. In 1993, MIT claimed a patent for "3 Dimensional Printing techniques" which were subsequently licensed to other companies, and the term has stuck since. Commercial 3D Printing machinery was initially bulky and slow, yet steadily has become faster. It was in 2005, though, that a hobbyist personal market emerged starting with the RepRap project, an open sourced model employing the fused filament model we are familiar with today, and ignited the awareness (and predictable hype) of the technology, able to fit on the future desktop. That isn't to say there are no further innovations in the commercial field—Mcor Technologies have put together a colour 3D printer that use layers of printed and cut paper to create 3D forms (although as you can see in this video, whilst the layering principle is present, the end object requires removal of unnecessary paper material). It does, though, resemble a technique closer to the original definition of printing.