(Photo credit: New York Times) The Harvard Art Museums are re-opening this weekend after a multi-year renovation by Renzo Piano, which has combined three museums into one, opened the rooftop and added, in typical Piano's style, glass bay windows flooding surrounding spaces with welcome light. Their re-opening coincides with the public display, for the first time in about half a century, of Rothko's Harvard Murals. Those murals were donated by Rothko to Harvard after he withdrew from the Seagram Building Commission, and installed in the university's Holyoke Center in the 1960s. Rothko made his own paints, and it wasn't known at the time that the specific mix he was using, Red Lithol, would fade under light exposure (the red pigment he was using was stable in powder form but not when mixed with the binder to make it liquid).
Thus, the murals today are extremely faded, and because of Rothko's specific technique, impossible to restore to their original condition without making irreversible changes to the work. A team of Harvard and M.I.T. research, according to the Harvard Gazette, investigated an experimental technique where colored light is projected from digital projectors hanging from the ceilings onto the panels to give the eye the impression of seeing the original colors. (The article states, "Light projection as a tool in art conservation was first described and demonstrated by Canadian conservator Raymond Lafontaine using slide projectors in the 1980s." Apparently he managed to remove the appearance of a yellowed varnish without removing the varnish itself, simply by projecting some colored light onto the painting to "absorb" the impression of yellow.)
I was dubious when I first read that the renovation of the Harvard Murals involved light projection, but the effect is truly stunning. If you look at the paintings from, say, two feet away, there is no way to guess this is not the real paint. From close enough, of course, your shadow comes onto the panel blocking the light from the projector and yes you can then see the faded paint in the same precise outline as the renovated image.
The Harvard murals differ from the paintings in three horizontal rectangular shapes stacked on top of each other, for which Rothko is best known; thus, it is particularly important for scholarship that they be put on view. They will undoubtedly broaden the knowledge by the general public of one of the leading Abstract Expressionists of his time. In the words of the Associate Curator of Modern and Contemporary Art: "One of the tragedies is the Harvard murals have not been recognized in art history in the same way they should be because they were taken down and because of the fading. One of the several things this exhibition will do is to bring them back into the discourse on Rothko’s history and the importance of them within his trajectory as an artist."
At the museum you can read a bit more information on the technological process used, which explains the approach in quite technical terms, but I haven't been able to find this online yet. In the meantime, this article in The New Scientist discusses the renovation in more detail.