The physical properties of copper change in the contact with moisture and air. Wrapped in a layer of patina, it takes on a variety of colors. They serve as a record of the passing time and of the characteristics of the place, where the phenomenon of copper patination occurs. The objects that come into physical contact with people are patinating in a different way. Their transformations become a symbolic monument to everyday human-object interaction.

Obol subjected to the passivation process, i.e. patina formation.