An exhibition titled "Decorated Copper Trays - sinia" is taking place in the Historical-Folklore and Natural History Museum of Kozani from the 28^th October 2007 until the end of April 2008, in cooperation with the Fοlklife and Ethnological Museum of Macedonia-Thrace. 

The display comprises authentic sinia from the collections of private individuals and organizations, from the Iviron Monastery of Mount Athos, the St Athanasios Monastery of Eratira, the family of P. Tzonos, as well as from the collection of the Historical - Folklore Museum of Kozani. The exhibition also features framed reproductions of the trays' decorative designs. Furthermore, there is a specially formed area with a coppersmith and a carver, who demonstrate their craft. The simultaneous video display brings to life an ancient craft and trade that has almost died out.

The sini was a large kind of baking tray of hammered copper, less deep than a baking tray. It was used to prepare pies and cakes. A larger and engraved sini was used as a formal table on a low base. In major milestones of life, the sini had ceremonial character as serving tray. Today, the copper, decorated sini is considered more as a work of art and used accordingly.

Kozani with its small towns, Siatista, Eratira, Servia, has a long tradition in copper-working, after Thessaloniki, where it is preserved until now. Through them unfolds a significant aspect of the country's everyday life and of the Greek tradition.