Specialty
Smoothing 3D printed parts
Layer lines vanish if you work the climb.
PLA and PETG sand cleanly with a four-grit progression. The trick is starting coarse enough to remove the layer ridges without melting the plastic from friction.
Beginner-friendly Twenty minutes per part 3 stages
The climb
The exact sequence, in order.
- 1 120
Remove layer lines
Hand sand. Light pressure — friction melts PLA.
Reach for
3M Pro Grade Precision Assorted Pack
- 2 220
Smooth the surface
Hand or sponge. Reach into details with the angled sponges.
Reach for
3M Angled Sanding Sponges (6-pack) — Wet or Dry
- 3 400
Final before paint or primer
Wet hand sand if you're going for the smoothest finish.
Reach for
3M Wetordry Assorted Pack — 600 to 1500 Grit
Watch out for
The things that quietly ruin the job.
- ·Work slowly. Pressing hard heats the plastic, smears it, and ruins the climb.
- ·For PETG, wet sand from 220 on — it's grabbier than PLA.
- ·Use filler primer for the deepest layer lines. Sandpaper alone won't fill them.
Questions people ask
The practical part.
Chemical smoothing vs sanding?
Acetone vapor smooths ABS without sanding. PLA needs sandpaper or filler — solvent smoothing doesn't work.
Keep going