Answer
For window trim before painting, use 180 or 220 to scuff, then 320 for fine visible edges.
Why it happens
Old paint ridges, gloss, and dust around trim need careful scuff sanding before paint.
Recommended grit
Use 180 or 220 for scuffing, then 320 for fine smoothing near visible edges.
Wet or dry
Dry.
Success check
The trim is dull, clean, and smooth before paint.
What to do
- Clean the window trim.
- Use 180 or 220 to dull glossy paint.
- Use folded paper near profiles and corners.
- Remove dust before painting.
Avoid: Do not scratch glass or surrounding surfaces while sanding trim.