Prototyping in general is one of the most valuable tools an engineer can use to convey certain concepts, moving from a 3D-CAD model to a physical representation of a design that can be analyzed and tested in the real world. This can be accomplished by utilizing injection molding and casting methods, 3D printing, and CNC machines. 

Additionally, rapid prototyping can include even simpler materials, such as paper, cardboard, wood, fabric, and even aluminum foil. 

​

Depending on where I'm at in the process of design and what I'm trying to convey, I will determine the best material to get the message and visuals across along with the functionality, with respect to both timing and cost.