Fra Angelico’s painting technique revealed by terahertz time-domain imaging (THz-TDI)

Abstract

We have investigated with terahertz time-domain imaging (THz-TDI) the well-known Lamentation over the dead Christ panel painting (San Marco Museum, Florence) painted by Fra Giovanni Angelico within 1436 and 1441. The investigation provided a better understanding of the construction and gilding technique used by the eminent artist, as well as the plastering technique used during the nineteenth-century restoration intervention. The evidence obtained from THz-TDI scans was correlated with the available documentation on the preservation history of the art piece. Erosion and damages documented for the wooden support, especially in the lower margin, found confirmation in the THz-TD images.

Quantitative Analysis of Minium and Vermilion Mixtures Using Low-Frequency Vibrational Spectroscopy

“…Accurate characterization of pigment mixtures is important not only for identification of artifact composition, but also to provide better understanding of artists’ palettes in original works, monitoring degradation of pigments over time, detection of previous damage including prior restoration and conservation efforts, and artifact authentication. ,, Raman and infrared spectroscopies have been utilized in the analyses of various pigment mixtures and binders, as demonstrated in recent reports. − From an analytical perspective, the multiple spectral signals from mixtures often present a practical challenge for spectroscopic analysis as compared to neat samples. Low-frequency vibrational spectroscopy has the potential to aid in pigment mixture analyses given the already reported successes using THz-TDS and LFRS for molecular solids, including pharmaceuticals. − Investigating pigments and their mixtures with low-frequency vibrational spectroscopy could also prove useful in elucidating the contrast mechanisms underlying the 2D and 3D images of artworks that have been collected using THz radiation. − …”