Value: How much light a surface reflects
(this is one of the 7 elements of art)
Form: similar to shape, but 3 dimensional and encloses volume
(this is another of the 7 elements of art)


Contrast is greatest next to an edge, notice the subtle
transitions of value to create contrast and form.

The light source will determine shadows.
Transitional values are used between areas of light and dark.
How do you know these shapes are round and not angular?

Edges will be crisp if there is a dramatic change of the planer surface
Contrast is greatest next to an edge - do not use line to define the shape once you have begun to paint.
How can you tell which areas are facing the light source?
Are there transitions of value on individual planner surfaces?

Painting by artist Susan Bennerstrom of Bellingham Washington

How did the artist create lighter and darker values?
Do you seen evidence of analogous color use?
Do you see areas of complementary color mixing?
Do you see areas were the artist have used white to make a value lighter or less saturated?

What is the difference between a shape and a form?

Cast shadows describe the environment and the object's relationship to it.


Determining the length of a cast shadow






The corner of the screen that comes forward does so because the contrast between the planes that form it is greater than that between the planes of the corner that recedes. If we isolate the middle of the screen so that we see no perspective, these corners still advance and recede.



Images excerpted from The Joy of Drawing by Bill Martin