What artistic technique is used to create an illusion of depth in a painting?

The technique that effectively creates an illusion of depth in a painting is linear perspective. This artistic method is based on the principle that parallel lines appear to converge as they recede into the distance, simulating three-dimensional space on a two-dimensional surface. Artists utilize vanishing points and horizon lines to guide the viewer's eye, making elements that are further away appear smaller and closer together, enhancing the perception of depth.

While color fading can contribute to the overall atmosphere or mood of a painting, it doesn’t specifically create a structured depth in the way linear perspective does. Texture gradient refers to the visual variation in texture perceived in an image based on distance, but it is not as systematic or defining for depth as linear perspective. Shape contrast might add interest or emphasis within a composition but does not inherently convey depth. Thus, linear perspective is the most effective technique for creating a convincing illusion of depth in visual art.