This study was created using the classical oil painting technique of painting on a toned ground. After painting a wash on the canvas and allowing that to dry, I drew the portrait over the toned surface. I then built up a monotone painting, capturing overall values. Then I built up the portrait with thin color glazes. Finally, I created more definition with thicker, more opaque color brush strokes, still allowing the ground in some cases to show through. Needless to say, there was a lot of dry time in between each step.
I'm in severe need of upgrading my brushes and oils. Since I rarely paint, I've held onto the painting supplies I've had since college.