Ghent Altarpiece study is a delicate art

When Anne van Grevenstein-Kruse was a child, her family made a pilgrimage from Antwerp to Ghent to see “The Adoration of the Mystic Lamb,” the celebrated 15th century altarpiece by Hubert and Jan van Eyck.

“It was still in its original chapel,” she recalls, “and I remember very well the old man who was paid to close the altarpiece and open it again.”

Made up of 18 painted panels, the work, also known as the Ghent Altarpiece, is widely considered a treasure of early Northern Renaissance art and an object of veneration in Art History 101. It also boasts a legacy so checkered that it could be lifted from a Dan Brown novel. It has been, at various times, sold off in parts and carried off as war booty.

After half a millennium, the altarpiece is miraculously intact, with only one smaller panel, depicting the “just judges” and stolen in 1934, replaced by a replica in 1945. It is also, remarkably, still in the church for which it was made: Saint Bavo Cathedral, formerly Saint John.

Anne van Grevenstein, an art conservator who teaches at the University of Amsterdam, along with Ronald Spronk, an art historian from Queen’s University in Ontario, Canada,head a team of art experts and trainees conducting a detailed technical analysis of the work, a project funded by a $230,000 grant from the Panel Paintings Initiative of the Getty Foundation.

In a side chapel of the church, most of the panels sit inside a protective glass enclosure. Several have been taken down for study, and another, the one of the just judges depicting 10 resplendently cloaked men on horseback, has been sent to Brussels to fix its flaking paint.

Van Grevenstein admits it’s ironic that this newest component of the work is falling apart the fastest.

When the team moved in with its equipment in April, the room had to be barricaded, with the only access through heavily reinforced security doors. Now the average visitor can view the altarpiece — and the work being done on it — only through a window. “As you see,” says Van Grevenstein, “we’re in a bomb-safe bunker.”

The Ghent Altarpiece is a complex work presenting the story of the Christian faith, especially that of redemption, told both on the interior with its two tiers (or in art parlance, registers) of panels, and on the exterior, which is seen when the altarpiece is closed. The main story is inside, with the idea of original sin introduced with Adam and Eve on the upper side panels and worship and salvation in the lower register, where groupings of prophets, apostles, martyrs and others gather reverently around the Sacred Lamb, symbol of Christ the Redeemer.

“They’re from the Old Testament and the New Testament,” says Hugo van der Velden, a Harvard University professor writing a book on the altarpiece. “It’s a catalog to all the saints to which people prayed, and all of them venerate the lamb of the Apocalypse.”

Jan Van Eyck introduced a new naturalism in the depiction of figures, their clothing and accessories as well as in the fauna and foliage in the background of the lower register. The trees, for example, are so detailed as to be botanically distinguishable — cypresses, olives, pomegranate and orange.

In his time, Jan van Eyck was arguably the most famous artist in Europe, says Van Der Velden. “The scale and the ambition of the painting make it perhaps the most important painting of the early Netherlandish art.”

When open, the altarpiece measures 13 feet high by 17 feet wide. It was commissioned by Joos Vijd and Elisabeth Borluut, a wealthy couple who also paid for the construction of a chapel. (They are depicted as piously kneeling figures on the outside panels.) Modern-day visitors see a replica of the altarpiece in that space, while the original altarpiece has been placed in another more secure one.

Even in the Van Eycks’ time the fame of the Ghent altarpiece spread through Europe — and it became deeply coveted. In 1794, French soldiers made off with the central panels. They were returned after Napoleon fell from power in 1815, only to have the wing panels pawned by the Diocese of Ghent. These were eventually purchased by the King of Prussia, and for decades they were proudly shown at the Gemäldegalerie in Berlin. When Germany lost World War I, it was forced to return the panels in the Treaty of Versailles.

The loss was not forgotten. During World War II, Hitler had the altarpiece seized from its temporary storage. The panels sat out the war first in a Bavarian castle, then, when threatened with bombing raids, in a salt mine. At war’s end, American troops recovered the altarpiece — and a hoard of other looted art destined for Hitler’s dream museum — and, in a royal ceremony, returned it to Belgium.

Before the current project began, several urgent questions had already been identified: whether the altarpiece is threatened by climate and air pollution, what the condition of the paint and panel is and how secure its location is. Van Grevenstein and Spronk emphasize that their work is just the beginning.

“We’re not restoring the work, we’re working towards a diagnosis,” says Spronk, known for his technical analyses of paintings. “If this is to be restored, I have no doubt the Belgian state will come up with the funds necessary. But it was hard to get it started, we have to do a lot of research, technical documentation.”

For him, “When the Getty agreed to fund this, it worked as a catalyst for everybody to come on board.”

Already completed work includes infrared reflectography, which allowed the team to identify areas that need closer study.

Seen during a recent visit to Ghent, the panel depicting the Old Testament prophet Zacharias has been placed against the wall for macrophotography, which allows investigators to look beneath the visible surface and Van Eyck’s brushwork. .

“Originally the figure was painted looking straight forward,” says Spronk. “But he was so high up that Van Eyck realized he had to look down. So you can follow the painter in correcting his composition.”

In the last century the altarpiece was subjected to X-ray photography three times. “What we want to do now is to X-ray details and compare them to the X-rays from the 1980s,” he says, “and see if we can trace cracks that become longer, joints that become wider, any degradation in the paint and ground layers and panel supports.”

Eventually, the material collected will be put online for other scholars to study. “It seems logical to do,” says Spronk, “but I don’t think it’s ever been done.”

By the end of the year, they hope to have recommendations for all those problems. “Conservation — fixing of flaking paint, removing surface dirt — that is a must,” says Van Grevenstein. “Climate and security is a must, but, for example, taking off yellow varnish is not a must, it’s a choice. You can say we will see Van Eyck better, but it’s not necessary for its conservation.”

Painting on wooden panels has been “a longtime interest of the Getty,” says Deborah Marrow, director of the Getty Foundation. “Many key paintings of the 12th to 17th century were painted on wooden supports. Of the 500 paintings in the Getty collection, 90 are on wooden supports.”

At the end of 2008, the foundation launched the Panel Paintings Initiative and set about identifying projects in need of funding — both to help the conservation of noted work but also to help train a new generation of conservators.

Conservation of paintings on wooden panels is a highly specialized field, restricted to perhaps a dozen people in the world. “We realized that most of those current experts will retire within the next decade,” says Marrow, “so we thought it was important to have a future generation who are properly trained.” Three conservators are being trained with the Ghent Altarpiece.

Asked whether working on the historic altarpiece would be different from working on another work of art, Van Grevenstein replies in her most objective tone: “In my profession, like the medical profession with its patients, we treat every painting with due respect.”

Still, a moment earlier she had acknowledged her feelings about the task at hand. “I am Belgian, and never did I think I’d be working on this someday,” she said.

calendar@latimes.com