What term describes the technique of blending colors in oil painting to create a smoky effect?

The technique of blending colors to create a smoky effect in oil painting is known as sfumato. This term, which means "blurred" or "smoky" in Italian, refers to the soft transition between colors and tones, allowing for a more atmospheric and subtle depiction of forms. Sfumato creates an illusion of depth and three-dimensionality in artworks, as seen in the famous paintings of Leonardo da Vinci, such as the "Mona Lisa." The technique relies on layering translucent glazes, allowing the artist to manipulate light and shadow in a gentle manner, effectively "smoking" the edges of objects.

Chiaroscuro, while related, specifically refers to the contrast between light and dark within a painting, helping to define volumes and three-dimensionality. Grisaille involves painting in shades of gray, typically used for monochromatic schemes, and unione refers to a technique where colors are mixed directly on the canvas, often seen in the works of Italian Renaissance artists, but it does not create the smoky effect attributed to sfumato. Thus, sfumato stands uniquely for this particular blending technique in oil painting.