What is value?

Value is the lightness or darkness of a color. In the video, you see a gradation of black pencil ranging from 100% black to a pure white. It takes some practice to control the shading making this gradation. By controlling values you describe the roundness of any form.

Not every color has the same value range. For example, much lighter colors such as yellow or light brown have a much shorter value range. Learning to see the value (or shades) of every color is a skill that an artist gets with practice. 

Before you begin shading, make sure your pencils are sharp. Sharpen them constantly throughout your drawing process, as it greatly affects your ability to shade the picture evenly and to have minimal texture. 

Color gradation means applying your tones from light to dark in a gradual manner with subtle transitions of values. This technique is often necessary to describe the roundness of the form.