In which scenario would an engineer select an inexpensive plastic as build material?

Selecting an inexpensive plastic as a build material is most appropriate when creating a conceptual model of a part. In this scenario, the primary goal is often to visualize the design, communicate ideas, or test fit and form rather than to produce a functional or durable end product. Conceptual models are typically used early in the design process, and since the focus is on aesthetics, form, or basic functionality, the performance characteristics of the material are not critical at this stage.

In contrast, other scenarios, such as producing durable end-use products or high-performance components, require materials that can withstand stress, wear, and other environmental factors. These applications demand more robust materials that often come at a higher cost. Similarly, producing finished parts also necessitates the use of materials that meet specific performance and quality standards, which are usually not satisfied by inexpensive plastics suitable only for conceptual modeling.