Which technique involves the optical blending of spots of color?

The technique that involves the optical blending of spots of color is Pointillism. This method, developed by artists such as Georges Seurat, relies on the use of small, distinct dots or strokes of color applied in patterns to form an image. When viewed from a distance, the eye merges these individual spots of color, creating a fuller and more vibrant perception of color and light in the painting.

Pointillism emphasizes the interaction of colors, where the viewer's eye plays a crucial role in the blending process, as opposed to physically mixing pigments on a palette. This technique allows for a vivid luminosity and depth in works, setting it apart from other art movements and methods.

In contrast, Cubism focuses on breaking down subjects into geometric forms and presenting multiple viewpoints simultaneously, while Impasto is a painting technique that involves applying paint thickly so that brush strokes or palette knife marks are visible. Chiaroscuro, on the other hand, refers to the use of strong contrasts between light and dark to give the illusion of volume in modeling three-dimensional objects and figures.