The art of engraving wonderful patterns by chisel (Ghalam) and hammer on metals is “Ghalam Zani”. The artist should have keen eyes and skilled hands. Numerous tools of engraving and the harmony of the artist's hand, hammer and the tools will make magnificent objects. This art date backs to Sasanid era and still, the most beautiful objects are produced by its different methods.
It would take months for a student to learn how to take the hammer in hand in right angle and how hard should he struck not to engrave it too deep or too shallow to make all the pattern on the same level. The light hammer sounds on Isfahan traditional bazaar is a like a delightful music.
Today "Ghalm Zani" is mostly on copper because they are harder but if you want to buy more precise one you could find silver and gold object too and you will be surprised by their exquisite fine pattern.