Methodological approach for in situ spectroscopic analysis of modern reverse paintings on glass: A case study of Kreuzabnahme (1914/15) - an outstanding example by Carlo Mense

. A non-invasive methodological approach has been carried out to identify the pigments and classify the binding media of the reverse painting on glass Kreuzabnahme (1914/15) by Carlo Mense. Mense was a member of the group Rhenish Expressionists around August Macke and got interested in the technique of painting on the reverse side of a glass panel. The studied painting indicates a remarkably painted reverse and front side, which creates a unique visual appearance of the glass. The applied non-invasive, spectroscopic approach includes X-ray fluorescence, VIS spectroscopy, Raman spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy. The measurements revealed inorganic pigments mixed with drying oil as binder. Together with common pigments, such as lead white, barium sulphate, bone black, cinnabar, chrome yellow, ochre, and viridian, an unusual additional material was found, strontium white.