A unique art form: The friezes of Pirgí

In the village of Pirgl, on the Greek island of Chios, the façades of hundreds of buildings are completely covered with gray and white friezes. Circles, squares, triangles and rhomboids are used to create a lively geometry, ranging from the straightforward to the complex, to give each house its distinctive identity, its own unique face to display to the world. While analyzing the frieze designs, the authors discovered that the frieze artists intuitively obey a unique set of color-reversing rules. The goal of the project was to explain this powerful art form and to discover the essential mathematical structure underlying these color-reversing friezes.