The material analysis of works of art aims to better understand the techniques of the ancient cultures and to preserve the cultural heritage for future generations. The analysis brings to light new and unique information for authentification, for conservation and more generally in the domain of history of artistic techniques. Until now, the methods were intensively developed and adapted to the specific, precious character of the works of art. Works of art are examined from the macro to the micro down to the nano scale thanks to TEM, atomic force microscopy, ion beam techniques, or synchrotron radiation spectrometries.
The artefacts created in the past had printed in the matter itself some tracks which may be first rediscovered as the different scales, from the macro to the nano. The second step of the scientific process (and perhaps the most difficult one) is the integration of the results inside the problematic stated by the art historians. Their questions should be translated in analytical procedures, and then, the results have to be superimposed with those got by the more classical study in Human Sciences. That the way to reach original conclusions, valuable to rediscover the fantastic invention of our ancestors in all domains.
Lustre is one of the most fascinating surface decorative effects produced on glazed ceramics. This technique seems to have been born in the ninth century in factories created by the Arabs during their conquests in the Orient (Mesopotamia, Egypt and Persia). Arab potters spread their knowhow all over the Mediterranean basin, especially Spain. Italian Renaissance potters succeeded in applying it to their production. The technique is based on a specific firing of the glazed pottery in a reducing atmosphere in the presence of metallic salts. The result is a surface layer with a metallic appearance, exhibiting various colours, from gold to brown or red. This paper provides the chemical nature and the physical structure of ancient gold like lustre layers and compares them with contemporary lustres produced by a Spanish craftsman reproducing the traditional Islamic techniques. Various analytical investigations (atomic force microscopy, high resolution SEM, particle induced X-ray emission, Rutherford backscattering, TEM, X-ray induced photoelectron spectroscopy, time of flight SIMS and grazing X-ray diffraction) were carried out as well as investigations into the coloured appearance by spectrophotometry. A model of the lustre formation is proposed wherein the development of a new superficial glaze is described. Comparison between ancient and modern production shows how the techniques have varied through the ages.
References, further readings:
J.Castaing, M.Menu, 2006, Analysis of art works and nuclear physics at the laboratory of Centre de recherche et de restauration des musées de France, Nuclear Physics News16/4, 4-10.
M. Menu, C. Vignaud, 2006, L’analyse des techniques des peintres de Lascaux, Monumental, 98-103.
J.-P.Mohen, M.Menu, B.Mottin, 2006, Inside Mona Lisa, Abrams ed.
M.Cotte, E.Welcomme, V.A.Solé, M.Salomé, M.Menu, Ph.Walter, J.Susini, 2007, Synchrotron-based X-ray spectromicroscopy used for the sudy of an atypical micrometric pigment in 16th Century paintings, Analytical Chemistry 79, 6988-6884.
J.B.Jackson, M.Mourou, J.F.Whitaker, I.N.Duling III, S.L.Williamson, M.Menu, G.A.Mourou, 2008, Teraherz imaging for non-destructive evaluation of mural paintings, Optics Communication, 527-532.
G.Padeletti, G.M.Ingo, A.Bouquillon, S.Pages-Camagna, M.Aucouturier, S.Roehrs, P.Fermo, 2006, First-time observation of Mastro Giorgio masterpieces by means of non-destructive techniques, Appl. Phys. A 83, 475–483 .
