Answer
For plastic, use 320 or 400 for shaping, 600 and 800 for smoothing, then 1000 or finer for final refinement.
Why it happens
Plastic scratches and heats easily, so it needs light pressure and a controlled fine-grit sequence.
Recommended grit
Use 320 or 400 for shaping, 600 and 800 for smoothing, and 1000 or finer for final refinement.
Wet or dry
Wet for 600 grit and finer plastic finishing stages.
Success check
The plastic has an even surface without gouges or heat marks.
What to do
- Clean the plastic first.
- Use 320 or 400 for shaping or scratch removal.
- Step through 600 and 800 to smooth the surface.
- Use 1000 or finer for final refinement.
Avoid: Do not use heavy pressure or coarse grit on plastic.