Living in the shadow of Vesuvius: Analysis of the wall paintings of Pollena Trocchia’s Roman buildings across historical eruptions

Through a multi-analytical approach the research focused on the evolution of wall painting technology used for two decorated buildings in Pollena Trocchia buried by volcanic deposits of Vesuvius. The study highlighted a different stratigraphy (with two or three layers) of mortar-based supports. Volcanic aggregate was added to lime binder for rinzaffo and arriccio, whereas calcite and marble dust first, then organogenic limestones were used for intonachino. Pictorial layers, applied using fresco and mezzo-fresco techniques, were obtained combining common (e.g., ochre) and expensive pigments (e.g., cinnabar, aragonite, Egyptian blue), showing diachronic changes in raw materials selection and the refinement of decoration.