Shape: An enclosed area identifiably distinct from its background and other shapes. It can be bounded by an actual outline or by a difference in texture, color, or value surrounding a visually perceived edge. A shape has width and height, but no perceived depth. It is two-dimensional but can exist on a plane other than the picture plane.
Geometric Shapes: Simple mechanical shapes defined by mathematical formulas, which can be produced using the implements found in geometry sets: triangles, rectangles, and circles.
Rectilinear Shapes: A subset of geometric shapes, produced using straight lines, usually parallel to the horizontal and vertical.
Curvilinear Shapes: Shapes based on the sinuous organic shapes found in nature.
Biomorphic Shapes: Blobby shapes, reminiscent of single-cell creatures such as amoebas, derived from organic or natural forms.
Amorphous Shapes: A formless and indistinct shape without obvious edges, like, for example, a cloud.
Form: The apparent or actual solidity or three-dimensionality of a drawn, painted, crafted or sculpted object. The composition and structure of the work as a whole.
Mass: The apparent solidity of a form. The illusion of bulk and weight achieved by shading and lighting, or by overlapping and merging forms. In sculpture and architecture, it is the actual or apparent material substance and density of a form. It can be thought of as positive space.
Volume: The illusion of enclosed space surrounded by or implied by a shape or form, and the space immediately adjacent to and around a painted form. In sculpture and architecture, the space occupied by the form and/or the immediate surrounding space. It can be thought of as negative space or the absence of mass.
Plane: A continuous surface limited by edges
Figure: The recognizable object we are depicting; a human figure, vase, or flower, for example. Traditionally, it is described as a positive shape, the ground as a negative shape.
Ground: The unoccupied space in the picture. Traditionally, the ground is a negative shape(s); the figure a positive shape (Coincidentally it is also a name for the substrate onto which we paint).
Silhouette: The area bounded by the contours of an object, form or shape that has used dramatic value contrast to emphasize the characteristics of that contour.
Size: The physical or relative dimensions of an object/shape, or other element in a composition.
Scale: A ratio of the proportions or dimensions of a drawn object or scene to those of the original. When, for example, a drawing of a building is in the scale of one inch to ten feet, one inch in the drawing stands for ten feet of the actual size of the building. The relative size or extent of a visual image.
Shifting Scale: The act of making a shape, form, line, volume, etc. larger or smaller.
Hieratic Scaling: In early art and some non-Western cultures, size used to denote status or importance, making the subject of the painting- a saint or a king- larger relative to the minor characters.
Proportion: Compares elements to one another in terms of size, quantity, or degree of emphasis. It may be expressed as a ratio or may be a more generalized relativity.
Distortion: A departure from the accepted perception of a form or object, often manipulating conventional proportions.
Positive Space: Where the creation of elements, or their combination produces a objective or non-objective figure or field against a ground.
Negative Space: The unoccupied area of a composition. Often areas of negative space or shapes are just as active or more active than the positive space in works of design and art.
Implied Shape: A shape created or suggested by the psychological connection of spaces or their edges, creating the visual appearance of a shape that does not physically exists.
Motif: A designed unit that is repeated often enough in the total composition to make it a significant or dominant feature. Motif is similar to theme or melody in a musical composition. It is often referred to as the unit used in a pattern.
Pattern: Repetition of an element, unit or motif in a regular and anticipated sequence, with some symmetry.
Tessellation: A tessellation uses a net of congruent (same size and shape) regular (same length) polygons as its structure. There are only three nets that follow this rule: triangle net, square net, hexagon net. The unit or motif can be varied as long as the above structures are used (think of Escher).
Tiling: Making a pattern by placing simple geometric shapes next to each other.
Equivocal Balance: Compositionally is when one side of a vertical or horizontal axis is a flipped mirror image of the other side. With value it is an 50/50 distribution of black and white values.