Openwork or open-work is a term in art history, architecture and related fields for any technique that produces decoration by creating holes, piercings, or gaps that go right through a solid material such as metal, wood, stone, pottery, cloth, leather, or ivory. Such techniques have been very widely used in a great number of cultures.
The term is rather flexible, and used both for additive techniques that build up the design, as for example most large features in architecture, and those that take a plain material and make cuts or holes in it. Equally techniques such as casting using moulds create the whole design in a single stage, and are common in openwork. Though much openwork relies for its effect on the viewer seeing right through the object, some pieces place a different material behind the openwork as a background. Reference: Wikipedia. Below are some examples of openwork in silver wares.
Archaeological finds in ancient Mesopotamia indicate that filigree was incorporated into jewelry since 3,000 BC. Specific to the city of Midyat in Mardin Province in upper Mesopotamia, a form of filigree using silver and gold wires, known as “telkari”, was developed in the 15th Century. To this day, expert craftsmen in this region continue to produce fine pieces of telkari.The Egyptian jewelers employed wire, both to lay down on a background and to plait or otherwise arranged jour. But, with the exception of chains, it cannot be said that filigree work was much practiced by them. Their strength lay rather in their cloisonné work and their molded ornaments. Many examples, however, remain of round plaited gold chains of fine wire, such as those that are still made by the filigree workers of India, and known as trichinopoly chains. From some of these are hung smaller chains of finer wire with minute fishes and other pendants fastened to them. Reference: Wikipedia