The Picture Plane is the border between the fictive internal space of the painting and the real world outside of the canvas. (Read more after the Break)
The Picture Plane marks the transition between the viewer's space and the illusionistic and fictive space depicted within the painting. Artists occasionally show objects or figures touching or reaching toward the picture plane through the technique of foreshortening, the effect of this is to create the illusion that the object or the figure is transcending the fictive space and entering the real space of the viewer, outside of the picture place; thus creating the impression that the figure or object within the composition is emerging from the canvas to become part the spectator's reality. The key achievement is that this extreme foreshortening, merges the fictive space with the actual space which surrounds the painting, thereby making the painting appear to be more realistic.