Finishing or secondary operations encompasses a broad range of processes that change a manufactured part’s properties. Engineers can employ finishing simply to improve part’s appearance and reshape it to meet certain dimensions, or use it to enhance functionality, such as increasing strength, chemical resistance, electrical conductivity and more. Secondary operations basically turn raw parts into finished goods and this isn’t limited to traditional manufactured parts. 3D printed parts can also be enhanced with secondary operations, but much like designing for additive manufacturing, different processes and best practices apply. Throughout the product design and manufacturing process, engineers should also be thinking about how 3D printed parts can be finished. Determining the appropriate finishing operations depends on the additive process, material and geometry as well as the desired aesthetics and functionality. This guide explains the primary finishing operations additive manufacturing service providers implement for FDM and PolyJet 3D printing technologies, grouped by possible finishing objectives, and compatible materials and applicable design considerations.