Which technique can be used for post-processing to improve the surface finish of FDM prints?

Sanding and polishing is an effective technique for post-processing that enhances the surface finish of FDM (Fused Deposition Modeling) prints. FDM prints often exhibit visible layer lines and are generally not as smooth as some other manufacturing methods. By sanding the surface, you can remove the outer layer of material, effectively reducing the visibility of these layer lines. This helps in achieving a smoother finish. After sanding, polishing can further enhance the appearance by giving the print a more lustrous surface. This combination of techniques is commonly used in various industries to make 3D printed parts more visually appealing and suitable for their intended applications.

Increased print speed, using larger layer heights, and printing with a lower infill density do not contribute positively to surface finish. In fact, increasing print speed can lead to loss of detail, larger layer heights will make the layer lines more pronounced, and lower infill density can negatively affect the structural integrity of the print, potentially making any surface imperfections more noticeable. Thus, these options do not serve the purpose of improving the surface finish in the same way that sanding and polishing do.