Value

Value is what gives everything depth and dimension (as opposed to lines which flatten things out). 

Value is a range from highlight (the brightest highlight being white) to shadow (the darkest being black) and all of the tones in between.

Blending- to mix the values using a paper stump, chamois cloth, finger or rag.  This will smooth out the charcoal  or pencil lines and make them almost invisible.

Make sure to use a clean stump when blending the light areas. Stumps can be cleaned with very fine sand paper or a nail file. 

HELPFUL TIP: A dirty blending stump can be useful in applying very light values.