Scratch building is the creation of a model "from scratch" rather than a manufactured kit. True scratchbuilt models consist of parts made by hand and do not incorporate parts from other kits. These are rare. When parts from other kits are included, the art is technically called "Kit Bashing." Most pieces referred to as "scratchbuilt" are actually a combination of kit bashing and scratchbuilding. Thus, it has become common for either term to be used loosely to refer to these more common hybrid models.