Drawings, paintings and printed works are generally referred to as two-dimensional media. Now, it can be argued whether any physical work can ever be truly two-dimensional. Paper seems flat, yet it has a thickness and unevenness of surface that we can perceive as texture. Even books, as they are bound in layers, have a dimension of thickness or volume. Christian Leborg24 points out that two-dimensional forms are in fact abstract: they can be described and explained as concepts, but never experienced in reality — all real objects have three-dimensions, anything more or less is an abstraction.
When looking at a drawing, we are in fact observing the surface of an object. Art is capable of creating a sense of space without needing to physically recede or extend beyond its actual dimensions. The perception of depth is possible since the visual clues on paper reflect the way we see the space around us. These clues appear to us in the form of motion, focus and field of vision, perspective, scale, colour and tonal qualities. Being complementary and interconnected, any of these markers can be essential to evoking a visual-spatial experience.