Answer
Between chalk paint coats, sand lightly with 320 or 400 after the coat is fully dry.
Why it happens
Light sanding smooths dust nibs and brush texture without removing the previous coat.
Recommended grit
Use 320 or 400 lightly between fully dry coats.
Wet or dry
Dry.
Success check
The surface feels smooth and powdery dust is removed before the next coat.
What to do
- Let the coat dry fully.
- Sand lightly with 320 or 400.
- Wipe dust away completely.
- Apply the next coat or topcoat.
Avoid: Do not press hard or sand through the chalk paint layer.