How Leonardo did it

Alasdair Palmer talks to the French artist who has discovered the secret of the Master’s technique

How did he do it? Among the many great unanswered questions about Leonardo da Vinci’s ‘Mona Lisa’, that has long been one of the most puzzling. Part of the perennial appeal of the ‘Mona Lisa’, and one reason why, today, there is a perpetual crowd in front of it in the gallery in the Louvre where it sits, protected by thick glass, is that it does not seem possible that the ‘Mona Lisa’ was executed by a human hand. The amazingly fine gradations from dark to light, the completely smooth flesh tones imperceptibly changing so as to create the impression of the contours of the model’s face, seem to be beyond the capabilities of any mere mortal — not to mention, of course, that strange smile.

The techniques Leonardo used in painting the ‘Mona Lisa’ were not understood by his contemporaries, and he seems to have wanted it that way. Leonardo wrote a Treatise on Painting, but he was careful not to give anything away in it: indeed, it seems he deliberately described methods which he did not use, as if to ensure that posterity could never discover the ones he did. His pupils did not employ his techniques after their Master died. There was no school, no workshop turning out ‘Leonardos’ by the dozen. He had no imitators — and no one has ever attempted to forge a work in his late style.

So when Jacques Franck, a French artist and art historian, began working on Leonardo’s technique, he knew he was embarking on a difficult, complicated and long journey. What he didn’t know was how difficult, complicated and long it would be. ‘I first started copying the “Mona Lisa” when I was seven years old,’ he says. Franck is now 60. ‘Of course, I didn’t get really serious about it until I was in my twenties…’ He experimented with various methods. Once