Sketch is the earliest painting form and the oldest artistic language in human history. Simply put, sketch is a kind of monochromatic painting, and its unique charm was discovered in the Renaissance of15th century.

During this period, Italian painters Massachu and Da? Finch, Michelangelo and others invented and applied the principles of perspective, anatomy and composition, which provided scientific basis for the three-dimensional sense and space sense of sketch performance, and gradually improved the sketch. Since then, sketch has become a unique painting form in the world.

Structural sketch type or? Structure sketch? , is it? Line? As the main means of expression, it mainly expresses the structure of the form, abandons or weakens the light and shade of the form, and highlights the combination relationship of the form, that is, the sketch method of structural characteristics;

Light and dark modeling or proportion? Light and dark sketch? , a sketch form with light and dark tones as the main means of expression, is a sketch method that unifies the understanding of light and dark feelings and volume to shape and express the body.

Sketch generally has five elements: shape, structure, proportion, perspective and light and shade.

However, there are three areas in the sketch: light, gray and dark. When the light shines directly on the object, there will be such a relationship, and these three areas will naturally form on the object. Of course, glass, metal and other products will have some special phenomena, but it is still inseparable from the three major color areas of light, gray and dark.