3D Printing Post-Processing Guide: Sanding, Priming, Painting, and Smoothing for Professional Finishes
TL;DR: The fastest route to a professional-looking FDM print is sanding (120 → 220 → 400 → 600 grit), one or two coats of filler primer, a light re-sand to 600–800, then 2–3 thin coats of paint. If you want zero layer lines, use epoxy or UV resin coating for the smoothest finish, or vapor smoothing for ABS/ASA. Resin prints have fewer layer lines but need washing + curing + sanding instead. Budget for sanding time — it’s 60–70% of the whole post-processing job. ...