Spectrophotometric punctual and imaging characterization of pigments from the early 20th century Nuanciers Lefranc
Authors: Fontana R., Striova J., Barucci M., Pampaloni E., Dal Fovo A., Manca R.
Autors Affiliation: Analytical tools provide excitingly new and crucial information about paintings and artworks, generally not visible to the naked eye and not available by any other means. Non-invasive and non-contact methods are currently under constant development so as the integrity of the examined artworks can be maintained. The indisputable value of infrared reflectography is renowned among the conservation community. The method has evolved since 1990’s into the multi/hyper spectral modality. This means that instead of a single spectrally wide image, many images (so-called reflectograms) at well-defined adjacent spectral windows are acquired. In this contribution, we discuss the spectrophotometric characterization of the Nuanciers Lefranc pigments performed with the aim to create a database accessible to restorers, art historians, conservation scientists or other experts operating in the cultural heritage field. The measurements were carried out both with our visible-near infrared (VIS-NIR) optical scanning device with extended 380-2500 nm coverage as well as with a highly spectrally resolved Zeiss spectrophotometer (303-1700 nm). The two-fold character of the data obtained with the scanner in spectral and spatial domain allows analysing the output also as a set of images so that the pigments can be distinguished, for example, by false colour imaging.
KeyWords: Nuancier B; Lefranc; VIS-NIR imaging; Reflectance spectroscopy;