Resume
The aim of the chair is to conduct research into the use of powerful, newly developed imaging methods for the study of paintings, as well as to provide services and eduction in this field. For the latter, the chair intends to familiriase art historians, curators and conservators with these innovative imaging techniques, both in a theoretical and practical manner. To do so, a collaboration if anticipated between the University of Antwerp (Chemistry and Conservation Department) on the one hand and the KIK-IRPA, the KULeuven, and Belgian museums on the other hand.
Background
As early as the beginning of the previous century, several forms of electromagnetic radiation such as ultraviolet, infrared and X-ray radiation are used for the study of paintings. The radiation is employed to gain insight into the hidden and often very complex layer system that hides behind the visible paint surface. This insight is vital for three groups:
- art historians who study the genesis of works or the studio practice of specific artists,
- restorers who are faced with specific conservation issues (eg. Flaking paint layers) and
- staff and curators of museum galleries who try to keep the painting in the best possible conditions for future generations.
Thanks to recent technological developments, including the introduction of sensitive digital sensors with an increasing wavelength range, the efficiency of traditional image techniques such as X-ray radiography and infrared reflectography is increasing. In addition, a completely new technical development occured in the last few years, in particular the introduction of so-called 'analytical' or 'chemical' imaging techniques. Instead of directly registering the radiation that is relflected by or transmitted through the artwork, the radiation is first analyzed by means of spectroscopic techniques. In a next step, the resulting digital data is converted into one or more images by means of software. In concrete terms, the added value of this method is to found in the fact that it provides information about the materials present on and below the entire paint surface in a visual manner, and this in a non-contact/non-destructive manner.
This new method was introduced in 2008 by the AXES research group of the University of Antwerp in collaboration with Delft University of Technology. After an initial proof-of-concept in the particle accelerator in Hamburg (DESY), the technique was soon translated into a mobile device that uses macro X-ray fluorescence (MA-XRF) to scan complete paintings in the museum gallery or conservation studio, without the need to transport or sample the artwork. As the figure above illustrates, the final result is a series of images each showing the distribution of a specific chemical element (iron, copper, lead, etc.). Whereas a conventional radiography generates only one image in which all information is compressed, MA-XRF scanning produces a series of images, one for each chemical element. The figure shows how in this case a portrait of a peasant woman painted by Vincent Van Gogh was re-imaged. The overpainted image shows a strong stylistical resemblance with other studies of farmers that Van Gogh painted in the winter of 1884-'85 in preparation for his first tableau 'The Potato Eaters'. In addition, thanks to this experiment we see immediately which materials Van Gogh used for realizing this study portrait and where these are located exactly in the painting. Unlike traditional chemical point analysis, MA-XRF scanning converts numerical and spectral data into images that are easily readable by conservators. Briefly, one can therefore say that this innovative research method succeeds in combining the visual aspect of the existing imaging methods with the advantages of spectroscopic analysis.
The relevance of this innovative imaging method was quickly evidenced by the interest taken by museums and conservators worldwide. In a few years, more than a hundred works were studied in various European museums (including the Mauritshuis, the Van Gogh Museum, the Louvre, the Gemäldegalerie Berlin, the KMSKA, the KMSKB and recently in the conservation workshop of Ghent Altar Piece) and US institutions (including the MoMA and the Metropolitan Museum in New York City and the J. Paul Getty Museum in Los Angeles). In addition, National Geographic Channel devoted his first 'Belgian' documentary to this topic, entitled: 'Behind the science: hidden masterpieces (see youtube: http://www.youtube.com/behindthescience). The success of MA-XRF scanning prompted both the AXES research group and foreign groups to intensify their research into new scanning techniques.
In addition to this development in the field of X-ray imaging, a number of other important improvements occur regarding the imaging of paintings by means of visual and infrared light. All these so-called "hyperspectral" imaging methods provide much more information than traditional methods from which they are derived, but these techniques have yet to find their way into the daily practice of art historians, curators and conservators. In view of these future developments, it seemed appropriate to develop three types of acitivities within this chair: education, research and service.
Research
The research section mainly takes place within the Department of Chemistry, Faculty of Science of the University of Antwerp, more specifically in the AXES research group (Professor K. Janssens) which specializes in the development of non-destructive analysis and imaging methods. The research goal includes not only a further refinement of the MA-XRF technique, but also the development of new imaging techniques for example. by combined use of different imaging methods and advanced image processing. It is certainly the aim to further develop the technology in constant dialogue with art history and a conservation field and to respond to specific questions and problems peculiar to these two fields. Thus, it will also be studied in the research part to what extent MA-XRF can be adapted to explore other media besides paintings (works on paper such as illuminations, murals, historical photographs, stained glass, etc). The currently available MA-XRF device has already proven that it can be used for the following applications:
Visualization of overpainted compositions and pentimenti,Attribution and authentication (disputed) work,Identification of the materials used by the artist and painting techniques,Localization and digital reconstruction of colored pigments,For the final item, the digital reconstruction of colors that have disappeared by degradation, there is great interest in the field because it permits display compositions in a way that is closer to the image as it was originally intended by the artist. Although this is an application that needs to be further developed, the illustration on the next page gives an idea of the possibilities. It concerns the color reconstruction of a work that can be attributed to the Italian Renaissance artist Andrea del Sarto (1486-1530). This work is hidden beneath a portrait attributed to Sebastiano del Piombo (1485-1547). By combining the underlying 'Del Sarto' performance can be convincingly made visible again the images of the distribution of chemical elements lead (in white), mercury (in red) and cobalt (in blue).
Service
In addition to the substantive aspect, the chair also aims to encourage effective interaction between scientists and on the other conservators, art historians and conservationists of the heritage. The first group wants to know what specific questions and concerns exist among art historians and restorers to play optimally here with upgraded appliances, while the second group will benefit from the added value that the resulting technical progress in their discipline. To facilitate this, there will be chosen a central theme of the chair in consultation with the permanent partners (see below) that will be systematically examined. Concretely eg. One artist (Memling, Rubens, Van Dyck, etc.) are selected and then systematically works that were created are scanned in his studio in order to get more insight in that way in the studio practice and genesis. As mentioned, this issue has yet to be selected, in consultation with the partners. Finally, the device will be used to support the restoration treatment of a number of masterpieces in the collection of the partner museums.
Education
The educational component aims to make fast go-getting changes in imaging technology efficiently flow to the field of art historians and restorers. Each year, a number of masterpieces in Belgian museums are treated like eg. the Lamb of Van Eyck, The Seven Sacraments by Rogier Van der Weyden or The Holy Family with the Rubens Parrot. For these three concrete works has contributed to research on the basis of MA-XRF to the choice of optimal treatment. In this view, will be offering a course in scientific imaging master conservation-restoration cause these practitioners will be informed of the existence and potential of new technologies for non-destructive imaging and that they have an up-to -date knowledge when they enter the field. This profound experience of modern imaging methods will make them more competitive against their European counterparts. Therefore, these educational activities are integrated in the master course 'Innovative C-R technologies "of the UA Training Conservation-Restoration (Faculty of Design Sciences). Here it is the intention to use the additional funds acquired through the chair in order to significantly increase the quality of the offered theoretical and practical educational.
It is also envisaged that the chair will contribute to the professionalization and expansion of the training of the master art in Flanders. The aspect of 'technical art history, after all, occupies an increasingly important position in the selection of exhibitions and art historical study of important artists. Various research methods are used to make the (hidden) information accessible decided in the works on display for visitors to an exhibition or for the specialized art historian. For instance, the recent exhibition 'Van Gogh at work' (May 2013-January 2014, Van Gogh Museum, Amsterdam) dedicated to workshop practices and materials used by Van Gogh. An important part of his oeuvre is indeed hidden due to frequent on paintings by the artist himself. This is now visualized gradually and accessible for study. To the "discoveries" made using MA-XRF, inter alia, include a lost painting by Van Gogh wrestlers at the Antwerp Academy of Fine Arts and painted the rehabilitation of two disputed works. This exhibition attracted a very great interest of the public and press.
In addition to the educational activities at the UA campus, there will therefore also an aspect of the educational activities at the Catholic University of Leuven (Department of Art History, Faculty of Arts and Sciences) continue. In addition, the trainees of the Royal Institute for Cultural Heritage in addition to the master of these two institutions are also involved. Specifically, we propose to organize two courses: First, a theoretical course (3 to 6 credits, i.e. 30 to 60 hours lecture) with the underlying principles of several recently improved or developed imaging methods are explained. A syllabus will be provided for. Alternatively, a more practical course (3 credits, 30 hours) with each working in small groups around a work of art is in the collections or restoration workshops of the partners (see below), and with which is associated an art historical or restoration issue. Students can apply multiple guided traditional and innovative imaging methods themselves and compare in order to experience the advantages and disadvantages of each technique itself. This practical research will continue in the restoration workshops of UA-C / R, the KMSKA and the IRPA. These preliminary studies also serve as a natural introduction to the research area of the chair.