The mysterious Bella Principessa–a knotty problem

This weekend I finally got to sit down and watch PBS's Nova on the DVR and thoroughly enjoyed the episode on a brewing art history controversy. The question: is this drawing by Leonardo da Vinci?

Young Girl in Profile in Renaissance Dress or "La Bella Principessa"

I won't go through the entire debate–you can watch the episode (at least for now) online or read the excellent summary by Hasan Nizazi at his site Three Pipe Problem. The short version is that the drawing, in chalk and ink on vellum, was sold at auction as a 19th-century German drawing. However, several scholars and collectors have proposed that it is a lost work by Leonardo da Vinci. The Nova episode does a good job of setting out the debate, although it leans heavily toward endorsing the view of the painting's advocates. It's darn convincing, in fact. My impression from reading online is that, for Renaissance experts, the case is still very much in the air, with more scholars refusing the authenticity of the work than accepting it.

The stakes are so high, Leonardo's name so big, and the money involved so stupendous that it will take a slam-dunk to convince everyone. I'm not the least bit qualified to offer an opinion. If it isn't by Leonardo, it's got to be a very clever fake; someone would have had to go to a lot of trouble. Tiny points have such an Leonardo-esque ring to them. Look at the details of the eyes, the hair. They're lovely, delicate, even exquisite. Even the oddity of the format–chalk and ink on vellum is a really weird combination–has the sort of experimental perversity that smacks of Leonardo. The man was never content to do things as they had always been done or as others did them.

One point that the documentary didn't go into but that I thought was interesting was the detail on the woman's sleeve:

I fiddled with the color and contrast to emphasize the detail of the knotwork. One thing that we know about Leonardo is that he loved designing intricate knot patterns.

Leonardo da Vinci, Ceiling of the Sala delle Asse, 1498

Look at the detail of the intertwining branches from the ceiling of the Sala delle Asse, a hall that he decorated during his time in Milan–just a few years after he is supposed to have completed La Bella Principessa. Here's another example:

Leonardo da Vinci, Ceiling of the Sala delle Asse, 1498

Leonardo's obsession with knot designs was famously recorded by Georgio Vasari, said (not very flatteringly–he found it baffling that the artist would "waste" his time so many things other than painting):

He even went so far as to waste his time in drawing knots of cords, made according to an order, that from one end all the rest might follow till the other, so as to fill a round; and one of these is to be seen in stamp, most difficult and beautiful, and in the middle of it are these words, "Leonardus Vinci Accademia".

Sketches of knots show up in the notebooks, and several were copied and printed. The original of one magnificent example has been lost, but the printed copy is believed genuine:

Knot design after Leonardo da Vinci, 1490-1500

(For another gorgeous knot design, check out this one at the British Museum.)

Of course I'm not the first person to notice the knot design on the disputed painting; scholar Martin Kemp notes the similarity as well, and he, unlike me, actually knows what he's talking about. And it hardly settles the debate. While the use of a knot design can be used to support Leonardo's authorship, one could also argue that a really clever forger would employ exactly such a characteristic element.

Nevertheless, the knots are beautiful. And the girl is beautiful. I have to admit the first time I saw it my reaction was "Don't be ridiculous–that's not a Leonardo." But now I look at it and think "Well, of course that's a Leonardo." What's almost impossible at this point is to simply look at the drawing and see it for itself, leaving aside the question of its creator.

So what do you think? Is it Leonardo–or isn't it?