Innovative Imaging Techniques for Examination and Documentation of Mural Paintings and Historical Graffiti in the Catacombs of San Giovanni, Syracuse

TLDR: In this article, the authors presented a scientific and technical examination of two mural paintings and their historical graffiti located in the catacombs of San Giovanni in Syracuse, Sicily, using Reflectance Transformation Imaging (RTI), Infrared Photography, 3D Photomodeling and XRF point analysis.

Abstract: This paper presents scientific and technical examination of two mural paintings and their historical graffiti located in the catacombs of San Giovanni in Syracuse, Sicily. Reflectance Transformation Imaging (RTI), Infrared Photography, 3D Photomodeling are presented as innovative imaging techniques used to capture significant details of the palimpsest, along with XRF non-invasive point analysis. These methods were performed on the Philadelpheia palimpsest and on the arcosolium of the Madonna. RTI technique was tested as a valid tool to enhance the readability and documentation of the numerous historical graffiti covering some of the murals, which are of high interest to scholars since they are useful to reconstruct the cultural history of the site. The results of the infrared RTI were particularly powerful in their ability to document graffiti on deteriorated surfaces painted with earth pigments. 3D Photomodeling also proved to be a successful and handy tool to document the position of paintings and graffiti in context with one another. The examination of the two paintings was integrated with an analytical study of the palette realized with non-invasive XRF.