Engraving on metal receptacles made of copper, brass, gold and silver by hammer and steel chisels is called emboss working. Emboss working is a decorative method that ancient men innovated when they recognized metals existed in the nature and discovered how to work with them. Nowadays, emboss working is one of the traditional artistic fields in Iran which is placed in industrial-art category and in the metalworking group. This art of a millennium antiquity is one of the artifacts which is still practiced in Esfahan with all of its related methods and styles. At first, the object to be embossed is covered with bitumen; the thickness of bitumen must be as much as it can keep the form of the object and prevent from making a hole in it while hammering.
After covering the work piece with bitumen, the design is copied on the body by rubbing a piece of cotton smeared with soot that afterwards the sooted design is converted into a shallow carving with tip of a particular chisel.
In performing mental designs, these are done without prepared plan. Then, the design is engraved with half-length tipped chisel, full length tipped chisel and polisher tipped chisel. Chisels like Gorsoom, Yekto, Nimvar, Nakhoni, Badami, etc.
When the engraving is finished, bitumen is removed by heating and extra bitumen is cleaned. Finally, engraved surface is smeared with varnish then it is covered with soot so that the background and cavities of the work gets black.
This kind of embossing is the simplest and at the same time is the most common method. In the niello engraving or Jondeh Kari removing bitumen is done during two steps in a way that at first the surface of work is covered with bitumen then some parts of the design are engraved by a chisel of Jondeh Kari. After recoating the work with bitumen, the embossed parts at the back of the work are engraved again.
Embossed copper products are presented in red color or coated with a layer of silver or gold. One of the professions dependent on emboss working is whitesmithery in which a layer of tin coats the red surface of copper or yellow surface of brass to convert their color into white. The master of emboss working uses whitesmithery in order to make white the objects produced in this way. At first the work piece is tinned then it is embossed. The delicacy of design, uniformity of the whole body surface and exact manipulation of the design are the advantages of a good and lasting embossed work piece.