Raman spectroscopy is a widely used analytical technique in heritage science for identifying pigments. In this thesis, we characterised the Raman spectra of samples of various paint layers containing different pigments, such as lead–tin yellow, orpiment, minium, azurite, cinnabar, and lead white. We analysed and compared the Raman spectra of paint layers with different binders, including egg tempera and linseed oil. In addition, we compared the spectra of varnished and unvarnished samples, as well as reference samples and accelerated-degraded samples. This provided insight into how individual components and the degradation process influence pigment identification using Raman spectroscopy.
We then used the spectral library we had prepared to interpret the Raman spectra of an actual work of art. The artwork analysed was a painting attributed to Matteo Ingoli titled Worship of the Holy Cross, which is presumed to have been created in the 17th century. The artwork is catalogued under uniform heritage Identification (EID) 239. The aim was to verify the usefulness of the model samples for identifying pigments and other materials on an actual artwork. We identified the pigments cinnabar and lead white, and at one of the sites, we also identified beeswax, which was not present in the model samples.
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