In this detail of Dissolution, you can see a slight dot pattern caused by the mezzotint rocker. The more pressure the rocker has on the plate, the deeper the grooves and burrs, and the harder it is to scrape those burrs back down to the original smooth surface (hence why you can still see "tone" in the whiter areas).
Gallery 317 -- 317 Cannon St., Chestertown, MD -- *Open every Friday & Saturday, First Fridays & by appointment*