(1) Seals cut as works of art should excel in three aspects-- calligraphy, composition and the graver 's handwork.

(2) It's easy enough to draw a curved line with a pen or on an engraving plate with a graver .

(3) A blow struck at a specific weak point along the blade, that is, at a notch, would achieve a consistent break and a characteristic triangular end that could be subsequently retouched into a formal graver .

(4) Lines are cut into a metal plate using a tool called burin or graver .

(5) It is clear from illustrations in that report, however, that formal blade tools such as gravers and drills occur in that assemblage.

(6) Other tools, such as scrapers, gravers , drills, and notched flakes, accounted for only 4 percent of the formal artifacts.