Analysis with micro-Raman spectroscopy of natural organic binding media and varnishes used in art Original Research Article

Micro-Raman spectroscopy (MRS) allows the identification of binding media and varnishes in paintings. This non-destructive micro-analytical method has been used for the recording of spectra (1800–200 cm−1) of different types of proteinaceous (albumin, casein, gelatin, isinglass, fish glue), polysaccharide (starch, gum arabic, tragacanth, cherry gum), fatty acid (beeswax, linseed oil, poppy-seed oil, walnut oil, sunflower oil) and resinous media (shellac, dammar, colophony, sandarac, copal, elemi, Venice turpentine, Strasbourg turpentine, amber, mastic, dragon’s blood, gamboge). The Raman spectra can be used as a reference for fingerprinting unknown binders and varnishes. This is demonstrated by the identification of the binder and pigment in a sample of a medieval illuminated manuscript.