Answer
Clean first, use the least aggressive working grit, avoid skipping grits, and keep pressure light.
Why it happens
Scratches come from starting too coarse, skipping grits, pressing hard, or dragging debris.
Recommended grit
Start with the least aggressive grit that works and move finer in steps.
Wet or dry
Dry for shaping and prep; wet for fine finishing stages.
Success check
Each grit leaves a uniform pattern before the next grit is used.
What to do
- Clean the surface before sanding.
- Start with the least aggressive grit that still works.
- Use light, even pressure.
- Clean between each grit change.
Avoid: Do not drag dust, grit, or debris across the surface.