http://www.rogerkrausracing.com/
Something I found good success with is after painting in the letters and the Wingfoot and alloying it to semidry, I lightly scuff the outlining edges with fine grit garnet type sandpaper. It seems to define the edges very well and takes the paint off of the high spots on the edges. Give it a try, you'll see what I mean. Just don't scratch the inside of the painted letters.