Intaglio printmaking is the opposite of relief printing; here what is removed ends up being printed (6-5). Lines are cut into the surface of metal plates using either sharp tools or acids. The cut lines act as little channels that retain the ink after the plate has been inked by a roller and its surface wiped clean. Then a piece of moistened paper is placed over the plate. Finally, the paper and plate are run through a press, the heavy pressure of which forces the damp paper into the ink-filled grooves and thereby transfers the image. Like the letters in an engraved invitation, the lines of an intaglio print are raised, because each line on the paper was formed by being pushed into the cut channels of the metal plate.