Naturwissenschaften und Technologie in der Kunst; Akademie der bildenden Künste Wien; Schillerplatz 3; 1010 Wien
Research > Projects > Material Analysis > Historical Pigments Print

Material Analysis for Contemporary Art

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Synthetic organic pigments and their identification in works of art are subjects of increasing interest in art history and conservation science as nowadays up to 70% of the colour ranges of almost every artists' paint brand contain those modern organic colorants. Such materials were already used in early 20th century paints, but there are only few evidences on works of art published so far. Thus, a PhD project was initiated focused on synthetic organic colorants. A comprehensive study on the use of synthetic organic pigments and lakes in artists' paints of the early 20th century was encouraged based on the examination of the synthetic organic pigments and dyes of the historical material collection of the institute. The identification and classification of the colorants were facilitated by the results of Fourier transform infrared spectroscopy (FTIR) and energy dispersive x-ray fluorescence analysis (XRF); all data were processed as reference data and compiled in databases. Futhermore, the examination of paintings of the 1920ies (period of Viennese Kineticism by the painter My/Marianne Ullmann (1904-1994); courtesy of Wien Museum/Vienna) has been subject for investigations into the potential and limitation of the combination of energy dispersive x-ray fluorescence analysis (XRF) and Fourier transform infrared spectroscopy (FTIR) as well as polarized light microscopy (PLM) for the detection and identification of synthetic organic colorants in works of art. As FTIR spectra of unknown synthetic organic colorant samples are difficult to identify if they don't match one of the FTIR libraries spectra, an approach is presented to facilitate classification of organic pigments by multivariate statistical analysis of their FTIR spectra. Methods of multivariate statistical analysis were applied to data sets of FTIR spectra of the synthetic organic pigments in order to predict the class of such unknown samples. K-nearest neighbor classification (KNN) and partial least-squares regression discriminant analysis (PLS-DA) was performed to compute regression models for prediction of class membership. It could be shown that the class of synthetic organic pigments can be determined with a high success rate by multivariate classification of their FTIR spectra, and furthermore classification of unknowns was possible by PLS-DA. In addition, aspects of the acceptance of synthetic organic colorants in artists' paint were taken into account. The significance of those so called 'tar coal colors' as subject of the early 20th century painting material quality discussion was revealed by reviewing of German sources, painting technique journals and archival material of the period from 1884 to ~1940. Many evidences for the use of such colorants in artists' paints could be located in these sources. Results of this study hope to offer an in-depth understanding of the history of acceptance in the context of the use of the synthetic organic colorants through the early 20th century.

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Papers

A. Schäning, M. Schreiner, D. Jembrih-Simbuerger:
Identification and Classification of Synthetic Organic Pigments of a Collection of the 19th and 20th Century by FTIR.
Proceedings of the sixth Infrared and Raman Users Group Conference (IRUG6), Florenz 2004, Hrsg. M. Piccollo (2005), 302-305.

A. Schäning, M. Schreiner, M. Mäder, U. Storch:
Synthetische organische Pigmente in Künstlerfarben des frühen 20. Jahrhunderts: Möglichkeiten und Grenzen ihrer Identifizierung am Beispiel von zwei Gemälden um 1925 von My/Marianne Ullmann.
Zeitschrift für Kunsttechnologie und Konservierung 21/1 (2007), 87-110.

A. Schäning, K. Varmuza, M. Schreiner:
Classification of Synthetic Organic Pigments by Multivariate Data Analysis of FTIR Spectra.
e-Preservation Science. Scientific research for the conservation of cultural heritage, IRUG8 Proceedings (2009
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A. Schäning, K. Varmuza, M. Schreiner:
Synthetische organische Farbmittel aus einer technologischen Materialsammlung des 19./20. Jahrhunderts: Identifizierung, Klassifizierung und ihre Verwendung in Künstlerfarben
Uni*vers. Junge Forschung in Wissenschaft und Kunst; G. Bast, F. Bettel, B. Hollendonner (Hrsg.), Springer-Verlag Edition Angewandte (2010), 237-253.

Dissertation

Anke Schäning:
Synthetische organische Farbmittel aus einer technologischen Materialsammlung des 19./20. Jahrhunderts: Identifizierung, Klassifizierung und ihre Verwendung sowie Akzeptanz in (Künstler)Farben Anfang des 20. Jahrhunderts
Academy of Fine Arts Vienna, March 2010