This was a commissioned sketch from many images sent by email and grouped together. The lighting is very different on the sister on the left from the lighting on the other two, but there was nothing to be done about that. It was done with charcoal, black and white, on grey Canson paper. 11" x 14." It took me 9-10 hours of drawing and probably two hours preparation... emails, phone calls, preliminary sketches, etc. I vastly underquoted my price, turns out. But I'm pleased with the results.