When "Old Masters Now: Celebrating the Johnson Collection" opens Nov. 3 at the Philadelphia Museum of Art, it will indeed feature many Old Masters, all part of the museum's holdings for a century.

John G. Johnson, a prominent Philadelphia lawyer at a time when Philadelphia lawyers had a national reputation for shrewd success and impeccable taste, amassed one of the great collections of Western art in the country.

When he died in 1917, he left all 1,500-plus works to the city. Botticelli, Bosch, Titian, Rembrandt, Manet — Johnson collected them all, and they arguably provided the DNA for the museum's entire collection of Western art.

"Old Masters Now," roughly 100 works mounted to commemorate the centenary of both the Johnson collection and the Benjamin Franklin Parkway, will close Feb. 19.

Don't imagine all these paintings will be entirely familiar — even those that have been on view for most of the last 100 years.

This is an exhibition about how familiarity breeds curiosity and how curiosity fuels change — and sometimes transformation. You can return to a work of art again and again, and know it for the first time.

Conservation, restoration, and scholarship have altered the Johnson collection, in some cases radically — to the point where Johnson himself might not recognize what he was looking at.

The conservation lab in the Philadelphia Museum of Art’s Perelman Building. Dominating the lab late this summer were a portrait of Archbishop Archinto by Titian, two flexible blue ventilation tubes snaking from the wall, and several  large work tables.
DAVID SWANSON / Staff Photographer
The conservation lab in the Philadelphia Museum of Art’s Perelman Building. Dominating the lab late this summer were a portrait of Archbishop Archinto by Titian, two flexible blue ventilation tubes snaking from the wall, and several  large work tables.

The great collector, for instance, thought he had acquired 10 paintings by Hieronymus Bosch (1450-1516), a painter of little interest to other American collectors at the time. Scholarship and scientific analysis have knocked nine off the list — they may be great paintings, but they're not by Bosch.

A major feature of the exhibition will showcase the invisible work of curators and conservators that changes perceptions and even the physical works of art.

Take Rogier van der Weyden's Crucifixion, with the Virgin and Saint John the Evangelist Mourning (c. 1460), for example.

Rogier van der Weyden’s “The Crucifixion, with the Virgin and Saint John the Evangelist Mourning,” after a 1993 restoration.
HILADELPHIA MUSEUM OF ART, THE JOHNSON COLLECTION
Rogier van der Weyden’s “The Crucifixion, with the Virgin and Saint John the Evangelist Mourning,” after a 1993 restoration.

The gilt-background diptych that Johnson acquired not only now has no gold, but it is no longer even considered a diptych. The museum, thanks to a director's nagging curiosity, believes the Crucifixion amounts to a spiritual door that once sequestered an enormous sculptural altarpiece, now lost. The paintings were restored in 1993 to their original look, with a deep blue background — and no gold. Their use as elements in an altarpiece received scholarly publication in 2012.

Instead of being paintings on a wall, the paintings were themselves doors into the heart of a great altar, which Mark Tucker, the museum's director of conservation, argued would have been "a carved, gilded, [and] immensely intricate opulent interior." It was Tucker's curiosity that kept nagging, year after year, and that led to a new and revelatory interpretation. "This was one of the major altarpieces of the 15th century," he said. "No one even knew it existed. We know it existed because of what survives here.

"New questions get raised with every generation," he said. "Everyone brings different eyes, a different sensibility, different training. … So every generation that comes along is going to want to revise and update."

Out of storage after 40 years: ‘What on earth is it?’

Recently, at the museum's conservation lab in the Perelman Building, a large, five-panel painting by Joos van Cleve, Descent from the Cross (c. 1518-20), was laid out in pieces on a table — a patient still in the midst of resuscitation — necessary for its star turn in the Johnson exhibition beginning next month.

Lucia Bay works on restoration of Joos van Cleve’s “Descent from the Cross” (1518-20) in the Art Museum’s conservation lab.
DAVID SWANSON / Staff Photographer
Lucia Bay works on restoration of Joos van Cleve’s “Descent from the Cross” (1518-20) in the Art Museum’s conservation lab.

The painting had been in storage for four decades, until Christopher D.M. Atkins, associate curator of European art before 1900, was poking around one day a few years ago.

"We pulled this thing," Atkins recalled. "What on earth is it? This is really cool. What is this? Why is this not up? What can we do? Then we talked with Mark: 'OK, we can tell its condition is spotty. What's really going on? What do we really need to do so we can display it?' "

The painting had been relegated to storage, partially because of its "spotty" condition and partly because it was deemed a mere copy of van der Weyden's 1435 painting of the same name, now in the Prado.

Atkins doesn't see it that way, although he acknowledges that the figures mimic the ones in van der Weyden's painting.

"So it's a copy in that sense," Atkins said. "But the obvious difference is placing the scene within the landscape setting."

Van der Weyden's painting has a gilded, nonspecific background, whereas van Cleve set his Descent in a very particular Flemish landscape, with unusual rock outcroppings and contemporary Flemish dress and appointments.

"We understand copies and replicas and drawing inspiration so directly from the past in a different way today," Atkins said, referring to views of earlier generations of curators. "I'm super-excited. Unfortunately, we couldn't just put it out. It needed a lot of treatment."

Lucia Bay, an assistant conservator, has been working on the van Cleve for a year. Because the painting is on five separate panels, it has broken apart more than once over the centuries, losing paint each time. Cleaning and varnishing have also taken a toll, and the panels have warped.

Bay decided to have a supportive mold cast for the painting. Ingenious springs secure it while allowing movement.

"Wood that's painted on one side, the face and the back are going to respond differently to humidity," said Bay. "So it's very typical for a 500-year-old painting on panel to have a slight convex curvature, a slight belly to it."

After the show, Atkins said, the painting will go into the museum galleries.

"It's a significant addition by an artist of this stature, but also it plays so well with our collection," he said. "This is an important addition to our collection."

An extra measure of Titian

Across the conservation lab, lying face down on a large table, was Titian's Portrait of Archbishop Filippo Archinto, removed from its stretcher, resting.

Teresa Lignelli removes varnish from Titian’s 1558 portrait of Archbishop Archinto at the Philadelphia Museum of Art’s Perelman conservation lab.
DAVID SWANSON / Staff Photographer
Teresa Lignelli removes varnish from Titian’s 1558 portrait of Archbishop Archinto at the Philadelphia Museum of Art’s Perelman conservation lab.

The Titian is a mainstay of the collection, a masterpiece almost continuously on view since the museum took possession of it in 1917.

In 2015, in preparation for lending it for exhibition in Germany, conservators examining the painting realized that a planned thorough treatment of the work — the last was done in 1950 — would be a bit trickier than thought.

"It had these strips that were nailed down to all four edges, and when we took those off, we discovered that two centimeters of painting — of Titian — had been folded over and nailed to the edges of the stretcher," said Teresa Lignelli, senior conservator. "Yes, it quickly became more complicated."

Probably when the painting went to auction in Paris in 1863, it was removed from its original stretcher and glued to a backing canvas for support. The problem was the new stretcher didn't quite fit. The solution: Fold the Titian over the stretcher and tack it on.

"These edges were considered unimportant in the grand scheme of the composition," Lignelli said.

She has been removing the edges of the backing canvas, thread by thread, knocking out tacks without damaging paint, and then relaxing the edges of the canvas to ease creases 150 years in the making.

The whole work will be reassembled on a newly made stretcher with new margins woven into the backing canvas. Old varnish will be cleaned off, new varnish applied, abraded areas will be built up by careful retouching, which will also address tack holes.

X-rays of the painting confirmed, Lignelli said, that "the composition that we've now restored is what was there originally."

But the major change the painting has endured over time will not be altered in any way by conservators.

Titian used a blue pigment called smalt to give the archbishop's robes their distinctive purple color.

Smalt, however, degrades over time, and what was once purple is now simply red.

Lignelli wouldn't think of changing that.

"There's not much we can do about it in the sense that that degradation, that change is what you would call an inherent vice of the materials he was using," she said. "It's part of the painting's history."

"Old Masters Now: Celebrating the Johnson Collection"

On exhibit at the Philadelphia Museum of Art, Nov. 3 to Feb. 19.

Hours: Tuesday-Sunday, 10  a.m. — 5 p.m.; Wednesday & Friday main building open until 8:45 p.m. Closed Monday.

Admission: $20 (adults), $14 (students and youth 13-18), free for children under 13.

Pay What You Wish Admission
First Sunday of the month, 10 a.m.-5 p.m. and Wednesday, 5—8:45 p.m.

Information: or 215-763-8100 www.philamuseum.org.