Values: The relative degree of lightness or darkness on a scale of black and white.

Color-values: The relative degree of lightness or darkness of a particular color mixture.

Line/edge quality: The relative darkness, lightness, hardness, or softness of a contour or shadow edge.

Edge: The place where two pieces of paint meet. Edges are simplified into three types, hard, soft, and lost.

Form: The visible volume or configuration of a subject. The specific roundness of an object for instance the human body expression by its surface and anatomy.

Naturalistic: Created to replicate what is observed in nature. Derived from personal observation of nature, and attempting to convey it very accurately.

Turning the form: Arranging the values in a painting or drawing so as to express the roundness of a subject.

Grisaille: The method we used in the beginning - painting in black, white, and raw umber.

Monochromatic: Containing or using only one color (as in an underpainting when only using raw umber).

Unity of light (shadow): The clear separation between light and shadow. This separation can be observed when squinting while looking at a subject, or glancing at it in a black mirror.

Key: The interpreted relationships of values, in a drawing or painting, taken from observing the whole subject/picture plane.

Visual impression: The fall of light on a subject which can be well observed while squinting.

Gesture: The movement of the figure or form. A change in direction that can be conveyed through curves and angles. A straight line alone has no inherent gesture. Two connected lines going in different directions have a gesture. A curve represents this. The greater the arc and the bigger the change in direction the stronger the gesture. This can be represented using three lines, a straight, C curve, and an S curve.

Design: The interpretation of the underlying structure of nature as expressed through line and shape, something we consider constantly while constructing a drawing/painting.

Light effect: Created by an appropriate contrast relationship between light and dark values in a drawing/ painting.

Chroma: Purity or intensity of color.

Hue: The identity of a color in the spectrum or color wheel.

Structural symmetry: Where the forms of the body, particularly the head and torso are the same on both sides, when split down the middle. For example the features of the face line up on a horizontal access, and are the same distance from the center of the face. If you were to put a line down the center, one side should mirror the other.
Structural symmetry becomes more complicated as when the object turns the symmetry exists in the perspective. Structural Symmetry is the tracking and arranging according to the symmetry and perspective of the object.