Medium + Method: Acrylic. Brushes, toothpick.
The Backstory: Dark under light; this time varying the color underneath (see below). No retarder in the base; a little in the top coat (using older paint for both coats). Toothpick etchings. The toothpick worked better than the rubber chisel, but it caught the bottom layer a couple times, marring the finish in those spots.