The application of Raman spectroscopy to the examination of ancient art and
the identification of mineral pigments used in antiquity has been demonstr
ated successfully hitherto, However, the examination of modern objects of a
rt is hampered by the absence of a spectral library database of relatively
modern organic pigments and dyestuffs, of which there are a large number. A
zo pigments provide an example historically of a class of synthetic organic
pigments which have been adopted by artists. The Raman spectra of 21 azo p
igments were analysed and a protocol was established for their identificati
on. Using this database, two azo pigments from 1 mu g samples of 20th centu
ry paintings attributed to Picasso and Appel were characterized. Copyright
(C) 2000 John Whey & Sons, Ltd.