Conservation and preservation of historical monuments as well as of single artworks of our cultural heritage are receiving increasing attention. In the online magazine ChemViews, Austrian scientists take a view on the current technologies used for scientific analysis and documentation. Portable instruments, a combination of noninvasive spectroscopic techniques, and especially designed weathering cells will provide the data needed to develop strategies for better artwork preservation, they propose.
In artwork analysis, noninvasive techniques such as X-ray radiography, infrared photography and X-ray fluorescence allow the detailed investigation of the chemical composition of, e.g., historical paints. Knowledge of these data surely satisfies our curiosity--is this blue color made of Prussian Blue or indigo? How much lead white was used in historical pigments? It also enables the scientists to assess the deterioration paths of the pigments and materials over time, an issue that has gained increasing attention in recent times.
Manfred Schneider, Rita Wiesinger, and Wilfried Vetter from Vienna University of Technology and the Institute of Science and Technology in Art (ISTA) in Vienna, Austria, have reviewed the state-of-the-art technology used for the documentation and analysis of pigments and dyes in paintings as well as of metals and their alloys or stone in sculptures. They conclude: "Scientific investigations are indispensable for studying material degradation processes on heritage objects."
Especially designed weathering cells enable the scientists to monitor the dynamic degradation of metals and polymers in time-lapsed mode. For the observation of long-term atmospheric corrosion, racks are used with the model samples mounted on it, which will be exposed to the ambient atmosphere. This analysis still needs observation times of years. Apart from the characterization of historical pigments and paints, a recent focus has also been laid on modern paints such as the widely used acrylic colors.
Photographic techniques using X-rays and infrared reflectance technologies nowadays enable scientists to visualize underdrawings and retouches in valuable paintings without any physical sample taken from the object. These technologies are also used for noninvasive material analysis. However, compounded pigments and organic dyes are still difficult to detect with the standard techniques. The authors therefore promote "Science for Art" as a growing research area with the need to develop advanced analytical tools for better assessing the long-term dynamic behavior of the materials. This will provide us with the clues of how to preserve the objects of our cultural heritage.
About ChemViews Magazine
ChemViews magazine is provided by ChemPubSoc Europe, an organization of 16 European chemical societies. It publishes news and longer articles from leading authors to the global chemistry community as well as educational material. http://www.
About the authors
Dr. Manfred Schreiner is Professor and head of the Institute of Science and Technology at the Academy of Fine Arts Vienna and teaching at the Vienna University of Technology in analytical chemistry. His main research is in the fields of photographic documentation and digital imaging of artworks by applying visible, infrared, UV and X-ray radiations, non-destructive material analysis of pigments in paintings as well as objects made of glass and metals and long-term behavior of materials in art and archaeology.
Dr. Rita Wiesinger is Senior Scientist and deputy head of the Institute of Science and Technology, Academy of Fine Arts Vienna. Her research focuses on stability and analysis of art materials (especially metals, glass and polymers) as well as the development of set-ups to perform in-situ studies on material degradation processes.
Dr. Wilfried Vetter is Senior Scientist at the Institute of Science and Technology, Academy of Fine Arts Vienna. His main scientific interest lies on the non-invasive analysis of cultural heritage and contemporary art objects by using compound-specific spectroscopic techniques.