1. Black, white, and everything in between
Value
Black, white, and everything in between

2. Value refers to how light or dark something is
When most people hear the word value, they tend to think of money. However in art value refers how light or dark something is. Value includes every shade from white to black.

3. Value is separate from color
Color has value, but you don’t need color to have value. Think of a black and white picture. The things in a picture have color but the color has been converted to what is called grayscale. Drawings typically are done in grayscale.

4. Value is what makes a drawing look like a three dimensional form
Value is what gives the impression of three dimensional form. In this picture you can clearly see the difference between drawing a cylinder with just lines and a cylinder that has value added. You can tell the one on the left is a cylinder, but it feels flat compared to the shaded cylinder on the right.

5. When light hits a form it creates a consistent pattern of values.
When light hits a form it creates a consistent pattern. This diagram shows how light hits a sphere. Where the distance between the light source and the object are shortest, the light is the brightest. This is called the Highlight. As the distance from the light increases the object gets darker creating what is know as mid-tone. Eventually the sphere curves away from the light at what is called the terminator. This marks the division of the sphere into light and shadow. Light that doesn’t hit the sphere directly bounces off other objects in the environment back into the shadow. This lightens the shadow slightly, and is called reflected light. Finally the object itself blocks light from hitting other objects like the surface it rests on. This is called the cast shadow. It is important to note that the values blend gradually. Any sharp jump in value indicates a sharp change in the form and by definition spheres are uniformly round. This diagram is a direct top view of the object, however light is often arranged to hit the objects from above and to the side as in the following examples.

6. Sphere
Highlight
Here the light is above and to the right of the sphere. The pattern is consisted with the previous diagram its just seen from a difference angle. Here the value shapes wrap around the sphere in a repeating crescent pattern.
Midtone
Terminator
Reflected
light
Cast
Shadow

7. Cube
Highlight
A cube reflects light very differently than a sphere. A cube has surface with sharp changes in direction. Therefore the values on a cube change suddenly as well. The light is again coming from above and to the right. The top is the lightest surface because it is closest to the light. The right side is just a little farther and is slightly darker. Here the terminator is at the corner of the cube. There is a little reflected light at the back corner of the cube and a cast shadow on the ground.
Reflected
light
Cast
Shadow
Terminator
Midtone

8. Cylinder
Highlight
On a cylinder the value patterns are vertical stripes. The values follow the same progression from highlight to mid-tone to terminator to reflected light. The top of the cylinder has a very subtle gradient moving from near highlight to mid-tone because the light is coming from above.
Reflected
light
Cast
Shadow
Terminator
Midtone

9. Cone
Terminator
A cone is very similar to a cylinder with the main difference being that the value shapes echo the triangular shape of the cone. The value shapes are wider at the base and taper as the move up the form.
Reflected
light
Cast
Shadow
Midtone
Highlight

10. Adding value to your drawings will take them to the next dimension
The structure of drawing comes from accurately line drawing based on accurately placed reference points. But the addition of value transforms a drawing from a flat two dimensional picture into a type of sculpture. Understanding and correctly applying value to your drawings will literally take your drawing to the next level.