ABSTRACT
Apart from identification, fiber optic FTIR can additionally be very helpful in following the chemical cleaning of the artworks’ surface, especially when organic components (like old varnish layers) need to be removed (Ropret et al., 2012). However, the interpretation of fiber optic FTIR spectra can often be complicated due to the fact that the reflection present at the artworks surface is usually a complex process. The morphology of the paint layers as well as their thickness give rise to both diffuse and specular reflection phenomenon that may result in band shifts and changes in the shape of the IR peaks. In the last few years several papers including reflection spectra of both pure materials as well as original artworks have been published (Miliani et al., 2012, Vagnini et al., 2009, Rosi et al. 2007), nevertheless, the interpretation of reflection spectra is still the main limitation of this technique.
