“Whoever wished to see how nearly art could imitate nature was able to comprehend it when he saw this portrait. . . . The eyes had that luster and watery sheen which are seen in life, and around them were rosy and pearly tints, together with the eyelashes, that cannot be represented without the greatest subtlety. . . . The nose, with its beautiful nostrils, rosy and tender, appeared to be alive. The mouth, with its opening, and with the ends united by the red of the lips to the flesh tints of the face, seemed in truth to be not colors but flesh. In the pit of the throat, if one gazed upon it most intensely, could be seen the beating of the pulse. On a thin-grained plank cut from the center of a trunk of poplar, larger than usual for a household portrait, he applied a thick primer coat of lead white rather than a more typical mix of gesso, chalk, and white pigment. That undercoat, he knew, would be better at reflecting back the light that made it through his fine layers of translucent glazes and thereby enhance the impression of depth, luminosity, and volume.10 As a result, light penetrates the layers, and some of it reaches the white undercoat to be reflected back through the layers. Our eyes see an interplay between light rays that bounce from the colors on the surface and those that dance back from the depths. This creates shifting and elusive subtleties of modeling. The contours of her cheeks and smile are created by soft transitions of tone that seem veiled by the glaze layers, and they vary as the light in the room and the angle of our gaze changes. The painting comes alive. Leonardo used glazes that had a very small proportion of pigment mixed into the oil. For the shadows on Lisa’s face, he pioneered the use of an iron and manganese mix to create a pigment that was burnt umber in color and absorbed oil well. He applied it with brushstrokes so delicate that they are imperceptible, brushing on, over time, up to thirty fine layers. “The thickness of a brown glaze placed over the pink base of the Mona Lisa’s cheek grades smoothly from just two to five micrometers to around thirty micrometers in the deepest shadow,” according to an X-ray fluorescence spectroscopy study published in 2010. That analysis showed that the strokes were applied in an intentionally irregular way that serves to make the grain of the skin look more lifelike.11 Then again, maybe this is being too obsessive about a tiny, perhaps irrelevant, observation. Call it the Leonardo Effect. His skill of observation was so acute that even an obscure anomaly in his paintings, such as an uneven dilation of pupils, causes us to wrestle, perhaps too much, with what he might have noticed and thought. If so, it is a good thing. By being around him, viewers are stimulated to observe the little details of nature, like the cause of a dilated pupil, and to regain our sense of wonder about them. Inspired by his desire to notice every detail, we try to do the same. Also a bit puzzling is the issue of Lisa’s eyebrows, eyebrows, or lack thereof. In Vasari’s fulsome description, he makes a point of lavishing praise on them: “The eyebrows, because he has shown the manner in which the hairs spring from the flesh, growing thickly in one place and lightly in another and curving according to the pores of the skin, could not be more natural.” That seems to be another example of Vasari’s effusiveness and of Leonardo’s brilliant combination of art, observation, and anatomy—until we notice that Mona Lisa has no eyebrows. Indeed, a description of the painting from 1625 notes that “this lady, in other respects beautiful, is almost without eyebrows.” More than that, the painting conveys this unity not only across nature but across time. The landscape shows how the earth and its offspring have been shaped and carved and replenished by flows, from the distant mountains and valleys created eons ago, through the bridges and roads created during human history, to the pulsing throat and inner currents of a young Florentine mother. And thus she is transported into an icon that is eternal. As Walter Pater wrote in his famous effusion of praise of the Mona Lisa in 1893, “Hers is the head upon which all the ends of the world are come . . . a perpetual life, sweeping together ten thousand experiences.”18 Isaacson, Walter. Leonardo da Vinci (pp. 487-488). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (pp. 484-485). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (p. 484). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (p. 484). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (p. 483). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (pp. 482-483). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (p. 482). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (p. 478). Simon & Schuster. Kindle Edition. ”
