Leonardo da Vinci's "Mona Lisa" is one of the most famous works of Western art. Mona's beguiling smile and her incredible realism have intrigued art lovers and critics for centuries, and virtually every portrait artist since da Vinci's time has studied the painting for insight into his approach to painting. Leonardo used many different oil painting techniques to complete this masterful work of art, some of which he is credited with perfecting to a degree no artist had ever achieved before.
Verdaccio is a style of underpainting where tonal values are established in a monochrome, greenish-gray hue before overpainting additional colors. Verdaccio is especially effective for creating realistic flesh tones in oil painting, as it captures the appearance of veins under the skin and cool shadows when later covered with transparent reds and earth tone colors. Leonardo da Vinci is known to have used verdaccio in his work, as can be seen in partially finished paintings such as "The Adoration of the Magi."
Sfumato, an Italian term, translates to "vanished or evaporated." In contrast with the Florentine school of painters who heavily outlined their subjects, da Vinci perfected the technique of blurring and softening edges to be virtually imperceptible. This approach heightens the realism of the image, as Mona's face gently curves and fades into her soft hair, and her shoulders gently round to disappear into the background. To achieve this effect, da Vinci chose a uniform palette of mid-tone colors and avoided the most luminous paints for bright features. With heavy blending, the painting appears to the viewer as if from behind a cloud of smoke.
Glazing was another technique, besides choice of tonal palette, through which Leonardo da Vinci achieved his sfumato effects and realism. Glazing is the application of multiple thin, transparent layers of paint over an already painted surface. Glazing allows an artist to achieve extremely subtle variations in color and shading, without hard edges and brushstrokes to distract from the appearance of realism. Scientists studying the "Mona Lisa" have found up to 30 layers of glaze on areas of her skin, some only a few micrometers thick. Using multiple glazes also helps add to the sense of depth in the background and shadowed areas of the painting.
Leonardo da Vinci is credited with introducing the idea of chiaroscuro to the art world. Chiaroscuro is described as the use of light and dark to define three-dimensional shapes, where tone and value dominates over color and hue. He believed in dressing his figures in light colored clothing so as to help them stand out from the darker background, creating variety in bright and shadowed forms. Leonardo achieved a unity of tone by keeping every colored object within a limited range of values, unlike other artists who would vary hue and contrast. Later artists such as Caravaggio would take chiaroscuro to extremes for dramatic effect, but da Vinci used the technique carefully to reinforce his subtle realism.