OPEN AND CLOSED SHAPES – If you create two shapes that overlap and that have similar value and colors at the point that they overlap, then the two shapes will appear to “open” to each other. Or if a shape has a value near its edge that is similar to the value or color of the background, the shape “opens” to the background. If a shape has a hard edge and is distinctly different in value or color to the background or surrounding area, the shape is “closed” to the background.
OPTICAL MIXING – This occurs when small color fragments are organized in a tight pattern, appear to fuse, and, from a distance, appear as a single mixed color.
ORGANIC SHAPE – A shape based on forms from the natural world or suggestive or living organisms.
ORIENTATION – The horizontal, vertical, or diagonal position of a composition or design element.