Final answer:
The imaginary surface between the viewer and the object is known as the picture plane, a concept used to create the illusion of three-dimensional space on a two-dimensional surface through techniques like linear and atmospheric perspective.
Step-by-step explanation:
The imaginary surface that exists between the viewer and the object is called the picture plane. It is a conceptual surface that can act like a transparent window, giving the viewer the illusion of a three-dimensional space within a two-dimensional work of art. This is a fundamental concept in drawing and painting, where the artist manipulates this plane to create depth and perspective, often utilizing techniques such as linear perspective and atmospheric perspective. For example, linear perspective uses a set of parallel lines that recede into the horizon, appearing to converge and give a sense of depth. On the other hand, atmospheric perspective relies on the visual phenomenon that distant objects appear smaller, hazier, and less distinct to imply depth. The mastery of the picture plane enables artists to create realistic or even illusory details, like in a trompe l'oeil painting that deceives the viewer's eye with highly lifelike imagery.