DEWALD

An earlier method of preparing the plate seems to have been by means of the roulette, and other tools of the same genus, especially the large barrel form with rim, lined and hatched, called the engine (21). The method of the earliest mezzotinters differed very essentially in the fact that it was largely a positive process. They roughened the plate where they required their darks, left the parts which were to appear white untouched by the roulette or "engine," and so scarcely needed to use the scraper at all.