I want to say something about the mezzotinting process. You have a copper plate and a 'rocker' which is a curved, serrated edge. You use the rocker to put thousands of tiny indentations onto the copper plate, kind of like making pixels that will print black. Once the plate is completely covered with the dots, you can start to polish parts of the surface back. The more you burnish, the less ink it will hold, and those parts print white.
I rocked these two small plates a long time ago but I was too afraid to polish them back until last weekend when I decided enough is enough!