Metal engraving is a process in which a design is incised on a piece of metal using an engraving tool. This form of decorating metal has been around for five thousand years. The tools are pressed into the metal to cutting it and forming the desired design. The harder one pushes the engraving tool into the metal, the wider the mark. The correlation between dipping depth and engraving width is determined by the top angle of the tool.
Engraving tools are made out of hard steel that cuts the design onto metal surfaces such as steel plates or copper. Engraving tools are available in a variety of sizes and shapes for making different lines and marks. The three most commonly used tools are called the chisel, the graving tool (also called bulino), and the burin (also called ciapolla).
The chisel is not used for cutting, but is hammered. This does not remove any of the metal, but depresses it. A pliable support is placed underneath to prevent the metal from breaking or buckling.
Gravers are halved carbide round rods with a cutting edge. The graving tool has a wood handle making it easier to control the depth of the cut made with this sharp steel tool.
The burin is also a sharp steel tool, but comes in different shapes (lined, rounded and flat) to produce different effects.
The two most popular kinds of engraving decoration are damascening and niello.
Damascening is metal inlay in which a fine metal plate is inserted into a grove that has been made in a differently colored metal, and then is beaten in.
Niello is a mixture of silver, tin, lead, and copper that has been fused. This heated mixture is used to filled an engraving in a precious metal. After the mixture cools, the face plate is polished to bring out the semi-opaque design.
Engraving produces a unique quality of mark characterized by steady, clean edges. These lines and marks are produced by specific tools designed just for that purpose. This is a very specialized form of art with many types of materials and designs that takes years to master.