The art of shading is developed by learning to recognise volume as represented by the pattern of light, medium, and dark values of the subject before you. Once you have understand the pattern of light, then shading becomes very easy.

Let me share with you some terminology about the art of shading .

Tone: local tone is the most general value of an art work. It can be light, medium or dark but it does not matter. What is important is that an artist is able to express the drawing in a series of varying tones.

Hight light: It is the most concentrated spot of light on the drawing. Highlight appears on smooth surface.

Cast shadow: Produced by an opaque object that gets in the way of a light source.

Form shadow: Produced when an object turns itself away from the light source. It is the darker side of an object form.

Reflected light: It is light that bounces off another object and comes back to reveal the form. It is always lighter than the highlight of the drawing.

In the art of shading, always observe the objects that you are drawing. Look at the subject matter as it is important to establish an order for seeing and receiving information about the subject you are drawing.

It is always good that you build a drawing from the general to the specific. You should always see and record the overall structure of the subject you are drawing first, before getting into the details.

For example, when drawing an apple, determine the order in which you want to build the pattern of lights and darks that it presents. Observe the subject you are drawing before picking up your pencil to draw. Do not fall into the mistake of most people, that is drawing without planning.