Enamel
The art of decorating the metal surface with glowing colors was known in Iran from early times. The framework of the enamel dishes is usually made of copper. The coppersmith master makes the dishes according to any ordered shape and size.
After the copper vessels are ready, they are rinsed in the hydrochloric acid solution so any layer of oil or other material is removed. Then the dishes are glazed and heated each time in 600 to 900 degrees centigrade.