Art 124A/B – Petrosky Vocabulary List
I. Line
Line – The pathway of a moving point usually made by depositing material on a contrasting surface.
Gesture – the essence of a subject captured in the quickest and most economical way. Usually consists of quick and extended gesture.
Axis – The imaginary centerline of a volume; the centerline is assumed to run in a volume’s longest dimension is called the long axis, the centerline running at a right angle to the long axis is called the short axis
Hatching Lines – A series of short, parallel strokes used to build up tone.
Crosshatching Lines – Consecutive sets of strokes is added over the first hatching lines at different angles to build even darker tones.
Implied Line – The condition of an absent line, but implied edge, that describes the presence of an important contour needed to complete a form. Used to depict a strong light falling on a smooth, unbroken surface, overlapping forms of the same or similar value or the turning away of a form.
Cross-Contour – Lines drawn across the surface of a form to depict the surface topography of that form.
Calligraphic Line – Literally, beautiful writing. The beauty of line becomes a major aesthetic aim.
Rectilinear – Lines relating to the quality or state of being straight or an object or form characterized by straight lines (square, cube etc.)
Curvilinear – Lines relating to the quality or state of being curved or an object or form characterized by curved lines (circle, sphere, etc.)
II. Shape and Volume
Geometric – Shapes and volumes such as circles, spheres, squares, cubes, cylinders, triangles and cones seldom seen in nature as perfect forms, serve as forms that underlie natural forms or form the basis for actual human-made objects.
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Organic (or Biomorphic) – Shapes and surface structure of forms in nature.
Volume (Form) – Any three dimensional form, regardless of identity, structure or size.
Mass – The effect and degree of bulk, density and weight of three dimensional volume in space or effect of a two dimensional shape consisting of value, texture or color on the picture plane.
Shape – The quality of a space (2D) or object (3D) in whole or part dependant on its outline.
Positive Shapes (Space) – In drawing serves as the subject of the drawing. In the figure ground relationship it is usually the figure and opposite defined by negative shapes (space).
Negative Shapes (Space) – In drawing serves as the shapes or spaces around the subject or positive shapes (spaces). Must be equally considered as visually important as the positive shapes.
III. Space
Plastic (3-Dimensional) – In drawing to treat the surface of the picture plane so as to create the illusion of depth, either shallow or deep, using representational or non-representational subject matter (as a window).
Decorative (2-Dimensional) – In drawing to treat the drawing surface in such a way as to affirm its two dimensional nature (as an object).
Perspective – A system (one, two and three point) by which the dimensions and spatial relationships of forms are represented on a flat surface to create an accurate depiction of form and space in the picture plane.
Trompe L’oeil – Literally “fool the eye”, subject is drawn so that the eye is deceived into perceiving the forms and spaces are real.
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Aerial Perspective – The use of blurred or softened contours and dimmed or dulled colors (tending towards the blue) to suggest space by imitating the visual effect of atmosphere intervening between the observer and objects at a distance.
Figure – Referring to the subject of the drawing or the positive shapes (forms, volumes).
Ground – In drawing referring to the spaces around the subject also called negative space.
Figure/Ground Relationship – Referring to the designed interplay of positive shapes and forms with negative shapes and forms so as to
