Impact of LED-based lighting on selected historical pigments

At the University of Pannonia pigment ageing experiment is carried out in order to determine the effects of LED lighting on several compounds of artistic pigments from different art periods, binding material and varnishes. These complex systems as test samples are aged artificially in a spectrally tunable LED lighting booth, which contains 20 independent channels of different LED chains. Several techniques are used to measure and compare the aged and non-aged pigments: surface spectral reflection measurements, Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy. Colorimetric analysis highlights a relevant change in colour during the ageing treatment, whereas FTIR technique allowed us to identify specific difference in absorption, while the degradation of system components can be identified by Raman Spectroscopy at certain phases of the ageing process. This paper summarizes the spectral reflection measurement results after 4000 hours of ageing.