Rapid prototyping is now also seen as an integral part of the even larger but not well defined rapid tooling (RT) market. Concept modeling addresses the early stages of the design process, whereas RT concen- trates on production tooling or mold making. Some concept modeling equipment, also called 3D or office printers, are self-contained desktop or benchtop manufacturing units small enough and inexpensive enough to permit prototype fabrication to be done in an office environment. These units include provision for the con- tainment or venting of any smoke or noxious chemical vapors that will be released during the model’s fabrication
