Post-Processing: Sanding, Primer, and Paint

3D-printed parts carry layer lines on their surface; achieving a display-quality finish requires post-processing. The basic workflow is: support removal → sanding → primer → paint → varnish.

Start sanding with 120-grit and work up gradually through 240, 400, and 600; because PLA softens when it heats up, sand slowly and wet-sand whenever possible. Filler primer seals any remaining fine lines — two coats of primer plus an intermediate sanding will smooth most surfaces. Acrylic spray paints bond well to plastic.

Alternative techniques: acetone vapour smoothing delivers a chemical polish on ABS parts; epoxy coating (XTC-3D) gives a smooth finish without sanding; and resin prints are ready for paint with minimal preparation. Customers who want painted or fully finished delivery just need to add a note to their order.