Kitbashing or model bashing is the practice of making a new scale model by taking pieces out of kits. These pieces may be added to a custom project or to another kit. For professional modelmakers, kitbashing is used to create concept models for detailing movie special effects. Commercial model kits are a ready source of "detailing", providing any number of identical, mass-produced components that can be used to add fine detail to an existing model. Professionals often kitbash to build prototype parts which are then recreated with lightweight materials.