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Art has many enemies. There are the obvious ones like fire or violent protest, which can destroy a painting in seconds. And then there are those that creep up more slowly, including dust, damp and soot. They don’t so much destroy a painting as unmake it. A combination of smoke and ageing varnish can dull even the most brilliant masterpiece to an impenetrable murk in just decades.
But I have a confession to make. I love impenetrable paintings. The murkier the better. This isn’t because I like dull pictures, but because they allow me to experience one of the art world’s secret pleasures: restoration.
Cleaning pictures is usually done behind closed doors, even in museums, which is a shame because it’s one of the most exciting things to see. In fact, I sometimes buy paintings just because they need cleaning. There’s not only the excitement of the transformation, from murk to colour, but the emotional journey too: will I find a pristine masterpiece beneath the grime, or a wreck that was better left undisturbed?
I should say that I don’t clean pictures myself. I learnt that lesson the hard way (it turns out nail varnish remover won’t do the trick). But in 30 years of investigating Old Masters, I’ve been lucky enough to work closely with some exceptional conservators, watching them bring hundreds of paintings back to life. Some years ago I had the privilege of exposing the conservator’s skills to a wider audience, working with Simon Gillespie on the BBC series Britain’s Lost Masterpieces. We restored more than 20 works from museum storerooms, including works by Rubens, Titian and Brueghel.
One thing I learnt making the series is how few museums still have in-house painting conservators. Restoration takes time and is expensive, and for a finance department juggling more urgent priorities, such as keeping the lights on, those jobs are an easy cut. The result is a surfeit of important paintings sitting in storage, safe but unappreciated.
Happily, there is some external funding to help. In the UK, the greeting-card company Woodmansterne gives conservation awards annually. The European Fine Art Fair (Tefaf) in Maastricht each year gives a grant to support the restoration of a major museum artwork.
This year’s Tefaf grant, worth €50,000, will allow Dresden’s Gemäldegalerie Alte Meister to clean a painting by Rubens that I have long wanted to see restored: his “The Boar Hunt” of c1616. We considered restoring what is probably a second version of the same composition in Glasgow Museums for the BBC series, but decided that, without also cleaning the Dresden picture, scholars couldn’t make a proper comparison between the two. Now, thanks to Tefaf, they can.
The Dresden painting is in good overall condition, but its true qualities are difficult to see. Multiple layers of thick varnish give the surface a yellow hue (natural resin varnishes yellow with age), flattening the composition and deadening the tonal contrasts. Yet the painting’s provenance suggests it should be one of Rubens’ most effervescent hunt scenes. It is believed he painted it for himself before selling it to one of his most significant patrons, the Duke of Buckingham.
Removing the old varnish will reveal the vibrancy of Rubens’ brushwork and a greater sense of depth, as light and shadow reassert themselves. The figures, similarly liberated, will spring into life. As Rubens’ first version of the subject, Dresden’s “Boar Hunt” should, in theory, look considerably better than the second version in Glasgow, after cleaning. But there will be art historical trouble if it doesn’t. Might there have been a mix-up between the two versions somewhere along the way? There’s an old saying in the art trade: “Cleaning is the friend of a good picture, the enemy of a bad one.”
Cleaning a painting always carries a risk, which is why the best conservators are calm and unflappable. Use the wrong solvent and you’ll break through the varnish too quickly, damaging paint layers beneath. Generally, the older the varnish, the harder it can be to break through. Conservators first test a range of solvents on tiny, unobtrusive areas of the surface, searching for the precise formula that will dissolve the varnish carefully. A solid underlying paint layer gives a conservator confidence. An artist such as Rubens tended to use robust, well-mixed paint. This bodes well for the Dresden cleaning, and they have spent years researching their almost 40 paintings by him.
Other artists used less predictable materials. George Stubbs would sometimes mix wax in his paint, making such works notoriously difficult to clean. More fiendish still are those paintings deliberately given a warm hue when made. In the 18th century, people were so accustomed to yellowed paintings that artists such as Joshua Reynolds would use tinted varnishes to make their works sit more comfortably in dining rooms hung with Rembrandts. The Wallace Collection in London has left its best-known Reynolds, “The Strawberry Girl”, uncleaned because it contains too many of his experimental layers and pigments. Which is why the picture looks as if it has been covered in treacle.
Often, the greatest challenge for conservators is undoing the work of their predecessors. The craze in the early 20th century for transferring panel paintings to canvas sometimes involved disastrous losses, as the plane went through the paint layer. I once brought Simon Gillespie a painting by Joseph Wright of Derby that had been almost entirely repainted by a restorer in the 1960s, apparently for no other reason than they were determined to improve the work of one of Britain’s greatest artists.
Still, we’ve come a long way from the days when pictures were cleaned by the housekeeper with half a potato. The most essential work conservators do today is not the dramatic restoration that I find so addictive, but the patient work of preservation, from pest control to monitoring light. Whatever it takes to save art from its greatest enemy of all — time.
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