Somewhere in the narrow streets of Milan was the carpenter or panel-maker who supplied the wood for the Salvator Mundi. This kind of artisan was the first of several craftsmen involved in the execution of a Renaissance work of art such as the Salvator. They were often required to construct large and intricate surfaces for paintings, building up a flat surface from planks of wood connected with animal glues and grooved joints, and combining panels of different shapes into elaborate altarpieces with wings on hinges. But the creation of the walnut panel for the Salvator Mundi was a relatively mundane task, since it was cut as a single piece of wood; it is therefore all the more strange that it was so poorly executed.
Leonardo may well have ordered a batch of panels, since two other Milanese paintings of his on walnut wood have been scientifically analysed and shown to have come from the same tree. The size was standard for devotional paintings, for which there was a large demand among wealthy Italian families. Typical subjects were the Virgin and Child, various saints including John the Baptist, and Christ, carrying the cross, crowned with thorns or as the Saviour of the World. Such pictures were hung in the owner’s bedroom or private chapel.
Wood has to be prepared for painting with various undercoats, just as canvas is usually primed. In fifteenth- and sixteenth-century Italy, this was sometimes done by the artist’s assistants, but often by the panel-maker’s workshop. The Salvator Mundi’s panel was prepared more or less as Leonardo said it should be in his notebooks:
The panel should be cypress, pear, service tree or walnut. You must coat it with a mixture of mastic [also known as gum Arabic, a plant resin] and turpentine which has been distilled twice and with white [lead] or, if you like, lime, and put it in a frame so that it may expand and shrink according to its moisture and dryness … Then apply boiled linseed oil in such a way as it may penetrate every part and before it is cold rub it with a dry cloth. Over this apply liquid varnish and white with a stick …
Florentine artists had their wood panels prepared with gesso, a chalky substance, but Leonardo, in common with Milanese painters, preferred a mixture of wood oil and white lead as the ground. He had his ‘sized’ with a first layer of animal glue. Then two layers of undercoat were applied, one made of a recipe of lead white pigment, with little grains of soda-lime glass and a binding agent of walnut oil; the second of more white paint, mixed with some lead tin yellow and some finer glass. The result was a surface with an off-white colouring. The addition of glass was a familiar trick used by artists at the time to lift the brightness of their pictures and accelerate the drying of the paint. Light on a painting does not reflect only off the top surface of paint. If the layers are thin enough and partly transparent it can pierce through layers of pigment and be bounced back by fine granules of glass, creating an effect of translucence. For the final process of the preparation – I confess I do not know if this was applied in the case of the Salvator Mundi – Leonardo advised ‘then wash it with urine when it is dry, and dry it again’.
But the panel-maker had done an exceptionally poor job. Deep within the prepared panel, unbeknown to the artist who was about to receive it, behind the preparatory layers of oil, gesso and urine lay a hidden problem. Unlike the walnut panels on which Leonardo painted other famous portraits such as La Belle Ferronnière and Lady with an Ermine, the Salvator’s panel contained a large knot in the lower half, right in the centre. Such knots were usually filled in with vegetable fibres, wood filings or fabric, as the Florentine artist Cennino Cennini advised in his fifteenth-century painter’s manual. But, in a second oversight, difficult to reconcile with the expertise of Renaissance woodworkers, who well knew the properties of their materials, that was not done to this piece of wood.2 It seems that either the panel-maker or an assistant in Leonardo’s workshop to whom the task had been delegated was careless with the selection and preparation of the wooden panel, and the defect was then hidden under layers of primer.
Even so, Leonardo would surely have taken a look at the back of the panel and seen the knot. The likelihood of that raises a second puzzle. Leonardo is known to have been interested in the technical aspects of making a painting. It seems out of character for him to accept such a flawed surface to paint on, especially if the work was destined for an important client. In humid and dry conditions a knot like this expands and contracts at different speeds from the rest of the wood, so that if the panel, looking far ahead into its future, became dried out, or wet, it would push and pull, perhaps taking the panel to breaking point, and creating splits and cracks. Alternatively, a knot is a weak point, so that if the picture was one day to be knocked or dropped, it could split around the knot. The knot in the walnut panel on which the Salvator Mundi was painted was a gnarled, ticking time bomb.
* Historians see the ‘modern’ period as beginning around 1500. Often they refer to the sixteenth and seventeenth centuries as ‘early modern’.
CHAPTER 3
Squinting at a computer screen one day in his home office, Alex Parish discovered the Salvator Mundi. It was listed for sale in an online catalogue of an obscure auction house in New Orleans, the St Charles Gallery. This was in 2005, three years and a few months before Robert Simon would board his flight to London carrying the painting under his arm. Parish thought the picture looked promising, and the price was so low that it was worth taking a small risk. He remembers: ‘I had a recollection of a similar thing that had come up with Sotheby’s a few years before. I bought the picture because I know this is just the sort of thing other people like to speculate on.’ He contacted Simon, who had himself also spotted the picture, as he subscribed to the gallery’s mailing list and received a hard-copy catalogue by post. Parish suggested they buy it together, fifty-fifty, the same way they had jointly bought many works before. Simon agreed.
Until he discovered the Salvator Mundi, Parish was a small-time Old Masters dealer whose career in the art world had been full of false starts, along with the treadmill of low-value backroom sales.
The art world has a glamorous image as a global nomadic court presided over by latterday kings and queens – the blue-chip gallerists (gallery owners), artists whose work fetches million-dollar-plus auction prices, and multi-millionaire collectors, around whom swarm smaller galleries and dealers and emerging artists. In the second half of each year the entourage moves en masse from art fair to art fair: Basel, the FIAC in Paris, TEFAF in Maastricht, Frieze London, the Armory and Frieze New York, Hong Kong, Miami, taking in auctions in London and New York on the way, in a blaze of parties and packing cases.
And yet, this is only the sparkling surface. Behind the scenes are many other people who are not born into riches, who do not have a large designer wardrobe or a taste for high society, and who are drawn into the art business not so much by a love of art, which everyone gives as their primary motivation, but by their hunger for an experience much more exciting, akin to gambling or hunting for buried treasure. For them, the attraction is the exhilaration of buying a painting from the first show of an unknown graduate artist, in the hope that