Dragging - scruffing
The technique of applying paint over a rough surface, the goal is to create uneven appearance and untouched depressions. It results in broken areas of color with irregularities so that under color shows through. In the Intaglio printmaking process, dragging or scruffing is leaving a film of ink on the surface of the plate, resulting in a less stark contrast between the printed lines and the background. Source: Ralph Mayer, "A Dictionary of Art Terms and Techniques"