In 3D printing, its often about whether the material supports the application. To illustrate this, consider ULTEM 9085, a flame retardant high performance thermoplastic for direct digital manufacturing (a.k.a 3D printing or 'additive' manufacturing) and rapid prototyping.
ULTEM is ideal for the transportation industry due to its high strength-to-weight ratio and what is called it FST (flame, smoke, and toxicity) rating. It's also about aesthetics. Many customers wish to mask dirt or grease in mechanical system such as under the hood of a truck, or in the fuselage of an aircraft, or on the manufacturing floor. A black material avoids the need for paint jobs and hide scratches. And parts require far less 'finishing', a time saver.
There could be nothing more dirty than around the wheels of a transport truck. Watch and learn why truck fender and accessory manufacturer Minimizer uses ULTEM when creating both fender and mounting component prototypes:
Video of Minimizer mechanical engineer, Martin Larsen speaking about ULTEM 9085