A painting cheaply acquired is actually from the Flemish master Brueghel. The revelation involved detective work, and the restoration human saliva, writes Alastair Sooke.

For art dealers, the holy grail is coming across a ‘sleeper’: a painting, usually offered at auction, which has been mislabelled by the experts, and is therefore undervalued – sometimes massively so.

Perceptions of the same painting sometimes shift radically, almost overnight

Often, a sleeper will be described as a work ‘after’ an Old Master, suggesting that the artist who painted it was imitating a greater, and more saleable, talent. Eagle-eyed dealers endlessly scour sales catalogues, hoping to come across a lot that their gut tells them has potential. When they do, they bid for it at a knock-down price before building a case in its favour by conserving it and carefully investigating any leads about its provenance. Upgrading a picture is a form of detective work, and once the case has been cracked, the sleeper can reappear on the market as a bona-fide masterpiece – with a price tag to match.

We hear about stories like this in the news all the time – and it isn’t only pursuit of profit that generates new discoveries. Art historians, too, often debate the attribution of paintings, and their arguments can turn a picture from dross into gold. In other words – and this is the part that, to people outside the art world, can seem like black magic – perceptions of the same painting sometimes shift radically, almost overnight. One minute, a painting is unloved and overlooked; the next, everyone is cooing over it and calling it sublime.

So, how, exactly, does this happen? To find out, recently I visited the Holburne Museum in Bath, where preparations for a new exhibition, Bruegel: Defining a Dynasty, were taking place.

The exhibition, which opens on 11 February, is devoted to the famous dynasty of artists founded by Pieter Bruegel the Elder (c 1525-69), aka Peasant Bruegel, the painter of peasant scenes who is considered one of the greatest artists of the 16th Century.

Although Bruegel’s original composition is lost, more than 100 versions of it exist

At the heart of the show is a newly attributed oil-on-panel painting, from the museum’s own collection. Called Wedding Dance in the Open Air, it depicts revellers celebrating a rustic wedding in a forest. The fascinating story of its rediscovery and conservation offers a case study in how to spot a masterpiece – and persuade others that you are right.

The right stuff

For years – since at least the middle of the 20th Century – the painting, which was acquired by the collector Sir William Holburne during the 19th Century, was thought to be by an anonymous copyist or follower of Bruegel’s eldest son, Pieter Brueghel [sic] the Younger (1564/5-1638/9), who was also an artist.

Brueghel the Younger – he reinstated the “h” that his father had dropped from the family name – lived in Antwerp. There he established a workshop that produced affordable replicas of his father’s paintings. Take Wedding Dance in the Open Air. Although, in its case, Bruegel the Elder’s original composition is lost, more than 100 versions of it exist around the world – of which no fewer than 31 are attributed to Brueghel the Younger.

In 2014, shortly after her appointment as director of the Holburne, Jennifer Scott, a specialist in Dutch and Flemish painting, who had previously worked as a curator at the Royal Collection, visited the museum’s storeroom.

In this case, certain things jumped out through that murky surface – Jennifer Scott

Considering an exhibition about the Bruegel dynasty, she asked to see Wedding Dance in the Open Air. At this point, the painting appeared very dark, because it was semi-obscured by discoloured varnish. Yet immediately, she recalls, she thought the panel had “potential”.

“It sounds silly, but it’s instinct,” she tells me. “You look at something and think either, ‘Ooh, no,’ or, ‘Hang on a second.’ In this case, certain things jumped out through that murky surface.”

One thing that caught Scott’s eye was the successful complexity of the whirling composition: “It looks so good, and makes absolute sense,” she says. She also believed that, beneath the varnish, the colours would be “really vibrant”. Moreover, she was excited by the curving tree trunk on the right, because “it’s going around the figures, and that’s something we know Brueghel the Younger does: he puts in the figures and then the trees around them.”

Even for a work of modest size, the process for conserving and analysing a painting can cost up to £15,000

In short, the panel felt ‘right’. Scott had a hunch that it might be the only extant version in Britain of Wedding Dance in the Open Air not by a copyist or follower but, in fact, by Brueghel the Younger himself. All she had to do was prove it.

Conserving and analysing a painting, though, is expensive: even for a picture of such modest size (37cm x 49cm), the process can cost up to £15,000. So, before going down this road, Scott sought a second opinion. She invited the Flemish art specialist Amy Orrock to inspect the panel, and Orrock agreed with Scott. Feeling emboldened, Scott found a donor to fund the project, and sent the picture to Elizabeth Holford, an accredited painting conservator who has worked with museums for more than four decades.

Buried treasure

Early on, the painting was examined using infrared reflectography. This technique allows art historians to see through the uppermost layers of paint, revealing what lies beneath. The infrared reflectogram revealed the refinement of Wedding Dance’s underdrawing (the preparatory drawing executed before paint is applied). When Scott first saw it, she recalls with a smile, “It was a good day.”

Why? In part because the execution of the underdrawing was so confident and masterful. Also, because the underdrawing of the Holburne painting corresponded closely, in various ways, to other underdrawings that have been firmly attributed to Brueghel the Younger. “Brueghel the Younger is known for his complete underdrawings, which we found here,” explains Holford.

She passes me a head lens, so I can take a closer look, before pointing to several lines marking drapery folds in the dancers’ clothes. “Do you see how they end in little hooks?” she asks. “That’s typical.”

Filling in the bare spots with removable watercolour took six months

Moreover, Holford continues, the underdrawing is remarkably like the painting on top – which is another good sign: “It shows that the hand of the drawing is the same as the hand of the painting,” she explains. “It’s not just one thing by one person and then somebody else completing it. There is unity.” “Because the underdrawing is typical of Brueghel the Younger,” Scott adds, “and because the painting on top conforms to his style, that indicates that the painting is also by him.”

Scott and Orrock’s hypothesis is that Brueghel the Younger had, in his workshop, a painting or drawing by his father of the original composition of Wedding Dance in the Open Air, which he used as the basis for a working drawing or ‘cartoon’. He then used this cartoon repeatedly to transfer the design onto different panels that were primed for painting.

Case closed, you might think – except that picture conservation is a painstaking business, and there was still a tremendous amount of work to be done to reveal its true appearance.

Peeling away the layers

The painting had to be X-rayed to survey how badly it was damaged. Then Holford cleaned its surface with saliva (“It’s full of enzymes and surprisingly efficient,” she says). After that she used isopropyl alcohol to remove the uppermost layer of varnish, which was, she says, up to 100 years old (the chemistry is such that this runs little risk of damaging the painting). Next, underlying, older varnish was taken off with acetone, which also gently removed several clumsy ‘retouchings’ by earlier conservators.

Imagine wearing sunglasses at the Sistine Chapel, and then they were removed – Jennifer Scott

Eventually, after around three weeks’ work, like an archaeologist digging down through stratified layers of sediment, she had revealed the painting in its original state: the 17th Century brushwork of Brueghel the Younger. “It was absolutely terrific,” she says. “The brushwork was wonderful – so smart and exciting.”

However, some of the paint had flaked off – and, in several places, bare wood was visible. So, Holford secured areas of vulnerable paint using an adhesive called isinglass. “It comes from the swim bladder of the sturgeon,” she says. “I get it from the Caspian Sea because it’s a by-product of the caviar industry.” Then, the bare patches had to be filled in with gesso (a mix of glue and chalk used as a “ground” or preparatory base layer in a painting) and subtly modelled so that they didn’t appear, as Holford puts it, “horribly flat” – or obviously modern.

At last, Holford could begin her own retouching – carefully filling in damaged areas using watercolour – which, crucially, is easily reversible – to mimic the transparency of Brueghel’s thin oils. “Otherwise,” she says, “if you leave great big areas of loss in something so finely wrought, all you do is look at the islands, and your eye is distracted – you can’t read the composition as a whole. By closing those bits, suddenly it all pulls together. It’s amazing.”

This part of the process, Holford tells me, takes the most time. She estimates that, by the end, she had applied only “0.5%” of the paint now visible on the surface of the conserved picture. But this still took her six months, working full time. “I listen to a lot of Radio 4,” she says, smiling. “You go somewhere in your head and are completely in the moment.”

The results are spectacular. What before appeared to be a gloomy nocturnal scene, painted by an undistinguished hand, now glows with vibrancy and dynamism, and throbs with life. “It’s got a spontaneity about it,” says Scott. “It’s very fresh.” The painting even boasts a newly discovered background of beautifully painted trees suffused with lyrical daylight – which, inexplicably, long after Brueghel’s death, had been overpainted brown.

Scott will not comment on the new value of the painting – but a similarly boisterous, though admittedly larger, scene by Brueghel the Younger sold for more than £2.5 million at Sotheby’s in London last December.

The Holburne, of course, does not plan to sell its Wedding Dance – so why expend so much time and energy on the painting? “Because we’ve done right by it,” Scott says. “As a museum, it’s being at the top of your game.” She pauses. “Imagine if you went into the Sistine Chapel wearing sunglasses and then they were removed – it’s like that. Now people can see this painting as it ought to be.”

Alastair Sooke is Art Critic and Columnist of The Daily Telegraph

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