RESUMEN
(1) Background: This paper illustrates an innovative methodological approach chosen to study and map the colors of the medieval wall painting of Santa Maria Antiqua in the Roman Forum, one of the pilot sites of the EHEM project (Enhancement of Heritage Experiences: The Middle Ages). Digital Layered Models of Architecture and Mural Paintings over Time). (2) Methods: Two methods were employed to gather information about colors and mapping. Specifically, colorimetry was utilized for spot measurements, and hypercolorimetric multispectral imaging (HMI) was employed to map the same colors sampled through colorimetry. (3) Results: Chromatic data for all colors in the wall paintings were obtained in the CIELAB color space. Additionally, chromatic similarity maps were generated using the innovative HMI system, a multispectral imaging technique capable of obtaining color data information through advanced calibration software named SpectraPick® (Version 1.1). This comprehensive approach facilitates a thorough understanding of color characteristics and distribution. (4) Conclusions: The color measurements and mapping represent significant advancements in the interpretation of medieval wall paintings, which are often fragmentary and stratigraphically complex. This research sheds new light on the colors used and enhances our understanding of the original appearance of the iconographic patterns. Furthermore, it enables the reconstruction of colors that closely resemble the originals.
RESUMEN
In the present study, a diagnostic approach was used to analyze the wall painting in the apse of the Sotterra church at Paola, in the province of Cosenza, Italy. The Sotterra church is nowadays located 6 m under the ground level. The presbytery area houses valuable pictorial evidence attributable to different phases. The oldest painting, visible in the apse area, dates back to the 11th-12th centuries, and it represents the subject of the present study, while the later decorations are placed in a chronological range from the 14th to the 15th centuries. Due to the peculiar environmental conditions, the conservation of subterranean sites represents a debated issue and must be properly investigated. For this reason, in this research, noninvasive analysis and laboratory-based methods were planned to obtain information about both the composition of original materials and the mechanisms and causes of alterations affecting the wall painting in the apse. Simultaneously, an environmental monitoring campaign of the indoor climate for the duration of nine months was conducted. The results highlighted the use of natural mineral pigments such as ochres and earths. The analysis of the painting stratigraphy revealed that the mural painting consists of two plaster layers characterized by lime-based binder. Moreover, the presence of a high amount of calcium sulfate has been discovered; this latter result, combined with the monitoring of the microclimate, allowed for the establishment of the crystallization and the condensation risks which occur on the investigated surfaces.