Shadow is an image that occurs when light is blocked by non-transparent objects. As the twin image of its source, shadow completely owes its existence to the light and is an optical matter in terms of its relation to the light. It represents the areas on the object that light does not reach. With light, shadow reveals a three-dimensional structure of the object. It is a required element in painting to create a three-dimensional illusion of the objects. Shadow is an indicator of its source object and taking the form of its source object, it embodies the object on the surface it falls. Therefore, an indispensable relationship occurs between the shadow and its source object. If there is a shadow, there must be its source material. Because s...