How to Sand Primed State Shaped Frames

Using a high grit sanding sponge, lightly sand the entire front face of the frame.  Do this in a systematic manner so you don't miss areas.  This should be done without gloves so you can feel the surface to confirm you haven't missed anything.

Go around the edges with 220 grit sandpaper and sand off any hairy parts that are left after sanding the face.  Pay special attention around the picture openings.

Vacuum off the state with the shop vac using the brush attachment to make sure you don't scratch the surface.