Plastic 3D printing is one of the fastest and most cost-effective methods available for the iterative design, prototyping, and production of custom parts with Xometry. Rather than the material being removed from stock, as historically done with subtractive manufacturing processes such as CNC machining, 3D printing works by repeatedly layering small amounts of plastic to build a design from the ground up. This is done by providing the 3D plastic printers with a three-dimensional digital design file, commonly referred to as a computer-aided design (CAD) file. Once you have a CAD file for your design, there are a number of different 3D plastic printing methods that can be used to create your parts. Xometry uses industrial additive manufacturing to print parts in a variety of engineered polymers, from transparent prototypes up to flame retardant plastics used in aerospace.