Shading is a technique used in visual arts, such as pencil drawing, to create a sense of depth or dimension and express the relationship between the subject matter and a light source. Shading is very easy to achieve in pencil drawing by layering pigment in such a way that it creates a gradient from the brightest to darkest points of a drawing. This may be more difficult to achieve in mediums such as paint or pastel, which typically require introducing an entirely new color to the work, rather than simply layering more pigment.
Shading can also be used to create a sense of contrast in monochrome works of art where there is no color used for differentiation of subject matter. For example, shading can be used to create the sense that an apple is of a different color than the table it sits upon. Additionally, shading can create a sense of movement and emphasize a particular mood the artist may wish to convey through his or her work.