Editing Engraving (section)

===Tool geometry===
Tool geometry is extremely important for accuracy in hand engraving. When sharpened for most applications, a graver has a "face", which is the top of the graver, and a "heel", which is the bottom of the graver; not all tools or application require a heel. These two surfaces meet to form a point that cuts the metal. The geometry and length of the heel helps to guide the graver smoothly as it cuts the surface of the metal. When the tool's point breaks or chips, even on a microscopic level, the graver can become hard to control and produces unexpected results. Modern innovations have brought about new types of carbide that resist chipping and breakage, which hold a very sharp point longer between resharpening than traditional metal tools.