A 3D pen is basically something that looks like a bulkier version of an ordinary pen or a pencil, however, instead of using the traditional lead or ink that is used in pencils or pen, the 3D printing pen operates using plastic.The 3Doodler is a 3D pen developed by Peter Dilworth, Maxwell Bogue total diet and Daniel Cowen of WobbleWorks, Inc.(formerly WobbleWorks LLC). The 3Doodler works by extruding heated plastic that cools almost instantly into a solid, stable structure, allowing for the free-hand creation of three-dimensional objects.