Shading is the technique of showing tones or values on an object through gradual gradations for it to look ‘solid’ and have a three dimensional effect. Shading techniques allow you to weave layer upon layer of pencil marks to add a convincing form to your line drawing. Shading adds a sense of substance to your subject and produces a convincing tonal relationship. Drawings take on a three dimensional form when shaded properly.
To render shades correctly on drawn objects, the artist must carefully observe the source of light that is striking various values of tones or shades on the drawn objects. After realizing the source of light, the artist must study closely the reflections of the light on areas of the objects to know the lightest and darkest sections. After establishing the endpoints or extremes thus the lightest valued areas as well as the darkest valued areas, the remaining area with a mid-half tone between the two extremes is the middle value.
The tones are adjusted as many times to make it look realistic. It