Engraving machines such as the K500 or K6 by "Hell Gravure Systems" use a diamond "pen" to cut cells. Each cell creates one printing dot later in the process. A K6 can have up to 18 engraving heads each cutting 8,000 cells per second to an accuracy of 0.1 �m and below. They are fully computer controlled and the whole process of cylinder making is fully automatic. The engraving process with diamonds is state of the art since the 1960s.