Color Analysis of the Brancacci Chapel Frescoes: Part II

Abstract

The restoration work of the frescoes in the Brancacci Chapel (Chiesa del Carmine, Firenze) offered us the opportunity of recording about one hundred reflectance spectra of selected areas on the frescoes before and after restoration. Our previous research was mainly devoted to pigment identification. In the present paper, color analysis is performed by computing chromaticity coordinates, purity, and dominant wavelength, starting from the reflectance spectra previously recorded. Afterwards, color difference between restored and not-restored fresco is evaluated and its distribution examined. The obtained results are then discussed in connection both to the causes which produced the color modification and to the possibility of performing electronic restoration on paintings.

UV-Vis spectroscopy

“…Moreover, FORS can contribute to the identification of organic colourants such as dyes and lake pigments in a non-invasive way, which is difficult to do with other analytical techniques. Therefore, there are several works in which FORS has been applied in the identification of colourants on historical paintings, such as easel paintings [11,16] and mural paintings [15,[43][44][45], and on illuminated manuscripts [46][47][48][49]. While most of these FORS studies on colourants aim at a qualitative identification, some evaluate the possibility of obtaining quantitative data on the colourants present in a paint [50,51], using specific mathematic algorithms.…”

The ancient stained windows by Nicolò di Pietro Gerini in Florence. A novel diagnostic tool for non-invasive in situ diagnosis

“…The acronym FORS, which stands for Fibre Optic Reflectance Spectroscopy, was firstly introduced in the literature in the early nineties [1,2] to indicate a completely non-invasive spectroscopic methodology for in situ investigations of paintings. Indeed, non-invasive spectroscopic measurements using optical fibres were applied for industrial purposes since the early seventies, while their first application to the field of works of art was made at the National Gallery in the late seventies [3] and successively at the Victoria and Albert Museum [4].…”

Exploitation of the whole electromagnetic spectrum in art conservation studies

“…5,22 By limiting it to the visible range, the reflectance spectrum ( ) used to define colour can supply useful information for identifying also pigments. However, the narrow visible range is often insufficient for making a clear identification of pigments.…”

“…To the best of our knowledge, the first in situ investigation on the colour of frescoes was made in the 1980s, when the frescoes of Masaccio, Masolino and Filippino Lippi (Chiesa del Carmine, Florence, Italy) were investigated during restoration works. 4,5 A bench spectrophotometer operating in the 200 nm -900 nm interval, which was equipped with an external integrating sphere connected to the instrument by optical fibres bundles, was utilized. A twofold objective was attained: an evaluation of the colour after the cleaning procedure, and the identification of the artist's palette.…”