When I Explain To People...

...that part of my process is sanding down my painting between layers of paint, I often get confused looks. I don't remove all the paint, just the bumps in the surface. 

In sanding by hand, I can control exactly how much I take off. This makes the surface smooth by removing the brush strokes, so when things change in the second layer, there is no trace (or "ghost") of the first layer of paint. 

In the bottom photo, you can see how much pigment was left after sanding. Where the paint was thin, the pink of the ground layer pokes through.