Macroscopic XRF imaging in unravelling polychromy on Mycenaean wall-paintings from the Palace of Nestor at Pylos

The wall painting fragments from the Mycenaean "Palace of Nestor" at Pylos, are characterized by their high artistic quality, their unusual iconographic variety and the use of tempera and secco painting techniques. Systematic in-situ XRF analyses combined with the results of other portable and laboratory analytical techniques have already revealed a rich gamut of inorganic pigments with respect to the common Aegean "palette", including different white and black pigments, iron based ochres ranging from dark brown to orange and pinkish hues, manganese based umbers, natural copper based greens, goethite, Egyptian blue and organic purple dyes. Macroscopic X-ray Fluorescence (MA-XRF) imaging, although well-established for non-invasive analysis of historical or contemporary painted artworks has hitherto been applied in a few cases only regarding the study of ancient polychromy. The purpose of applying in-situ MA-XRF imaging on selected wall painting fragments from the Palace of Pylos was to evaluate the capabilities of this technique in identifying the composition of pigments and their spatial distribution within heavily deteriorated pictorial layers, and in revealing iconographic information invisible to the naked eye. The results of MA-XRF imaging allowed us to critically re-consider previous artistic reconstructions, providing significant evidence on the painting techniques and materials used by Late Bronze Age painters.