A complementary integrated approach using non-destructive optical and X-ray methodologies for pigment characterisation on an ancient Egyptian coffin

Abstract Museums and culture heritage institutions seek affordable, comparative, non-invasive imaging and analytical techniques to identify and study ancient materials and support their conservation. This study presents a multimodal research approach to assess the art-historical value of an isolated ancient Egyptian polychrome wooden coffin fragment from the KU Leuven archaeological collections, dating to the Third Intermediate Period (ca. 945–656 BCE). In a first step imaging techniques (standard even and raking photography, visible-induced luminescence, visible imaging spectrometry, white light and multispectral multilight reflectance imaging, narrow band multispectral imaging) were applied on the coffin’s surface to document its state, to identify and differentiate original and restored areas, and to select spots for more in-depth spectroscopic molecular and elemental analysis (fibre optics reflectance spectroscopy, X-ray fluorescence spectroscopy). These allowed pigment identification, characterisation of mixtures and provided a deeper understanding of the object’s condition and used painting techniques. All applied methodologies can be used in situ. The resulting datasets are curated into a multilayered IIIF Mirador 3 viewer, presenting all results in a complete and user-friendly environment. Graphical abstract