Final answer:
Artists use techniques like tonal variations, shading, hatching, and cross-hatching to create depth and form. These techniques involve varying pencil pressure, using different pencil grades, applying parallel lines, or crossing lines to build up darkness, and creating contrasts known as chiaroscuro.
Step-by-step explanation:
Tonal variations and shading are crucial techniques in drawing, used to simulate different light effects and create a sense of form and depth. There are several methods to achieve tonal variations and shading, each contributing uniquely to the artwork's overall texture and three-dimensional appearance. Let's explore some of these methods
Michelangelo's use of hatching and cross-hatching in works such as the Head of a Youth illustrates how these techniques create chiaroscuro (contrasts of light and shadow) to give form to his figures. Artists create shading through lines or tones, varying pressure, or by using different mediums dissolved with varying amounts of water, as is done with washes of ink or color.
These techniques are not only about creating light and dark areas but also about adding volume, creating three-dimensional illusion on a flat surface, and contributing to the artwork's composition by defining form, creating texture, and establishing a visual rhythm.