I thinned gloss black paint quite a bit, but not quite a wash. I shook the bottle, took off the cap, leaving a thin layer of black paint. I dipped a toothpick inside the cap, straight up, leaving just a little paint on the tip. I then touched it inside the dial. A couple of more drops and the paint flowed out to the rim. I used gloss black to simulate glass covered dials. I use flat paint for the panels. The glossy dials look just like glass instruments on a flat painted panel.