Engraving is the earliest of the intaglio printmaking processes, in which an image is engraved directly onto a metal plate, usually made of copper. It is a highly skilled and painstaking technique. A sharp tool called a burin is held in the palm and driven forward with pressure by the forefinger, gouging out the metal in lines composed of v-shaped grooves. The copper residue from the incisions is wiped away and the surface thoroughly cleaned before the plate is inked and passed through the press.