When light strikes an object, the objects casts a shadow in the opposite direction of the light source. In graphic design, fake shadows from an imaginary light source add interest and realism to the printed page. Drop shadows and cast shadows are common devices used to add interest to graphics and text used in page layout.
Role of ShadowsWhether in real life or created with graphics software, shadows serve a purpose. Shadows helps us determine the spatial relationship between us, objects, and backgrounds.
Shadows can tell us if something is floating above the surface or sitting on the surface. Shadows can reveal the shape of objects. When composing a scene, shadows can add contrast or color and can help to lead the eye to specific areas and tie elements together.
Drop ShadowsA drop shadow duplicates the shape and size of an object or text and makes it appear that the object or text is floating in front of the background. The drop shadow is placed behind the object and offset slightly depending on the position of the imaginary light source and the imaginary distance of the object from the background.
Cast ShadowsA cast shadow, also called a perspective shadow, adds a more realistic element of perspective. Instead of floating above or in front of a surface, the cast shadow anchors an object to one surface while giving the illusion of being in front of another surface.
Cast shadows look more like the shadow cast by a person or a tree or a building. Instead of floating detached behind the object it exends from the object out across one or more surfaces in front of, behind, or to the side.
Through rotation, stretching, and skewing the cast shadow mimics the shadows cast by the sun or other lights. A light almost directly above an object may cause a short, fat shadow. A light closer to the horizon may cause a long, narrow shadow.
Other Shadow EffectsThrough graphics software the designer can do other special effects similiar to drop shadows and cast shadows. A glow effect is like a soft shadow all around an object. Wind or motion blur creates shadows that make it appear the object is moving. 3D or embossing filters place shadows around the edges that give a raised lettering effect.
Another aspect of cast shadows are form shadows. When a shadow is cast it means that one side of the object is facing the light source. The side of the object away from the light source will be darker, softer, in shadow. Depending on the strength of the light, this form shadow may or may not be quite pronounced.