Originally Posted By sthemi
400 is typically OK for most paint, 600 is better for a smoother finish.
As the other poster said, when your substrate is looking shiny, the top coat has the best base to build to a shine instead of a rough surface to try to blend in.
The topcoat paints do not really fill in the sand scratches and they will be visible in the finished paint.


iagree Paint fills in/hides nothing. I've had good luck with painting over 400. What do the P sheets for the paint you want to use call for?