How AXA is supporting innovative research in art conservation

Authored by AXA XL

Since 2002 AXA has supported innovative research in art conservation through grants to individuals and organizations, including MoMA (Museum of Modern Art), Tate Modern and VITRA, whose scientific studies promise long-term contributions to preserving cultural assets. The overarching goal of these grants has always been to create knowledge and tools for extending the lifespans of artworks to future generations.

Consistent with its commitment to art conservation and preservation, AXA has awarded several grants to researchers investigating the effects of light on fine art. In 2010, for example, AXA funded a two-year effort undertaken by the Centre de Recherche sur la Conservation des Collections (CRCC) in Paris. In this project, the CRCC conducted extensive research on different measures for protecting works on paper—such as photographs, prints, drawings and watercolors—from damage caused by light exposure. Based on this work, the CRCC introduced a tool for alerting owners/exhibitors when sensitive paper-based objects were at risk of over-exposure.

That landmark study was followed in 2012 by a grant to two Harvard University research centers: the Center for Technical Study of Modern Art and the Straus Center for Conservation and Technical Studies. This project focused on five murals Mark Rothko painted on canvas for Harvard in 1962. Over time, the murals experienced severe fading due to a fugitive red pigment (Litho Red) in the paint, along with excessive exposure to natural light in the penthouse dining room where they were displayed. The murals incurred further damage during the 1970s when the space was rented out as a “party function room”; someone named Alan C., for instance, scribbled his name on one of them. In 1979, the by then severely faded and damaged murals were taken down and put into storage.

The research team investigated Rothko’s painting materials, techniques and stylistic development, and conducted chemical analyses on his paintings and the paper studies used to create the murals. Armed with the results of these analyses, the Harvard Art Museum, where the murals are now displayed, collaborated with the MIT Media Lab to recreate the original colors digitally because restoring the murals physically wasn’t feasible. Today, five digital projectors illuminate the canvases so that visitors experience the murals chromatically as they were initially displayed.

Interestingly, people often visit the Harvard Art Museum at four o’clock when they “turn off the Rothkos” to watch the colors revert to faded blacks and grays; it is a unique opportunity to observe these images both as they were and, almost simultaneously, as they are.

Developing an advanced micro-fading tester to assess colour change

According to one commentator, watching the Rothkos turn off is like “experiencing a transformation that took many years in a few seconds”—an apt description of what another current AXA Research Fund recipient is trying to accomplish.

Gauthier Patin is a Ph.D. candidate at the University of Amsterdam; he is also affiliated with the Van Gogh Museum. With AXA’s support, he aims to improve the field of micro-fadeometry both technically and methodologically by developing an advanced micro-fading device to assess color change in paintings. Patin embraced this topic after conservators and curators in the Netherlands noted how some colors in Van Gogh’s paintings have faded over the past twenty years. Although other researchers have identified the light-sensitive pigments responsible for these changes and studied their degradation mechanisms, we currently know little about the timescale of this problem. To what extent has the observed fading and discoloration in Van Gogh’s paintings now stabilized? And if still ongoing, how fast does it occur?

Patin aims to answer these and related questions by creating a device that measures the light sensitivity of individual colors on an object and then predicts how and how quickly they will change over time, depending on exposure to light of varying qualities and intensities. In other words, what kind of color changes would we expect to see in Van Gogh’s paintings over the next ten years or so under different lighting conditions?

The instrument, which in technical terms is called an ‘artificial accelerated light aging system’, has three main elements: the light source that causes colors to fade; a spectrometer that characterizes color in precise, quantitative terms; and a stereo microscope that serves as a connection between the light source and the spectrometer. It also includes a high-quality imaging system to document the fading. In contrast to earlier micro-fading devices, this setup enables Patin to change the parameters in the fading process without affecting the color measurements. That, in turn, creates the opportunity to better understand how different variables—e.g., light energy, time and pigment material—interact to cause colors to change.

To conduct a micro-fading analysis, Patin trains a concentrated beam of vertical light on a sample and measures the color every 10-20 seconds for anywhere from 20 minutes to several hours. This approach rests on the reciprocity principle whereby damages from a high dose of energy over a short time are like those from a small quantity over the long term. The light source could be from a Xenon lamp (representative of daylight) or an LED (representative of many museum illumination systems). The spectrometer defines the color at each interval based on the ‘CIELAB color space’, the widely used international standard that quantifies colors within a three-dimensional space. In other words, each color measurement is precise and empirical.

Benefit for the art world

The applications and implications of these innovations appear promising. One benefit lies in improving illumination systems and practices. For example, museums could ensure their illumination systems avoid or limit potential damage by better understanding how artworks by specific artists or from different eras are susceptible to color change. These findings would also be relevant for galleries and collectors with paintings from the same artists or periods.

Another application could be when collectors are asked to loan artworks to museums for special exhibitions. In this scenario, owners could impose conditions on how their pieces are displayed based on prior micro-fading analyses, including, for example, reducing the intensity of illumination or changing the quality of the light sources.

Patin’s device can currently perform local predictions showing how a specific portion of a painting will change over time and under certain conditions. In the next phase, he aims to extend the micro-fading analyses to entire objects (by extrapolating individual point measurements) and to such other media as tapestries and ceramics. He envisions developing software that would show virtually how artworks would fade over 20-100 years.

Creating that level of predictive capability will take some time. Still, it will be of enormous value to museum curators, gallery owners and private collectors looking to safeguard artworks for future generations.