This is from an evening class I've been doing at Maryhill Art School with Cynthia Bowles. It is a new technique for me, based on laying a layer of oil and turps first, then a layer of transparent oil paint (in this case, burnt sienna) and then rubbing out the lights with a cloth. The next week, we went back and put in the darks.
Can't quite see how to develop this further into full colour, but think I will be experimenting with the technique with other colours over the next wee while.