A study on Correggio wall paintings: characterization of technique and materials of Abbey Church of S. Giovanni Evangelista in Parma, Italy

This study deals the materials of the sub- arch of the Del Bono chapel of the Abbey Church of S. Giovanni Evangelista in Parma, Italy, datable around 1523. The author of the painting is Antonio Allegri, known as Correggio (1489 – 1534), considered one of the greatest painters of the sixteenth century. Optical microscopy, micro-Raman spectroscopy, micro-Fourier Transform Infrared spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and gas chromatography coupled with mass spectrometry were selected in order to provide the higher set of significant data, limiting as much as possible sampling. The analysis has allowed to identify the pigments, characteristic of the epoch. The Correggio’s palette is composed by mineral pigments, sometimes expensive such as lapis lazuli, azurite and cinnabar, together with a wide range of earths or by synthetic pigments like smalt blue. From the amino acid content determination through GC/MS it was shown that, for all samples examined, the protein fraction is to be attributed to the presence of a mixture of egg and animal glue, present as binders in the samples containing lazurite, smalt, hematite, green earth and goethite. This allows to assume the use of a secco technique, also with pigments that do not need the employment of organic binding media on wall. For the gilding sample the hypothesis is that Au foil had been applied on a brown background where the Au foil is applied on the oil-based missione.