Creating value and contrast in art serves multiple purposes. It helps create a sense of depth and dimension by differentiating between light and dark areas, highlights certain elements of the composition by making them stand out from the background, and creates a focal point by drawing the viewer's attention to a specific area of the artwork.

Impasto is a technique used to create texture in art by applying thick layers of paint to the canvas. It is not typically used for creating value, which is more commonly achieved through techniques such as chiaroscuro, sfumato, and stippling.

Sfumato is the term used to describe the gradual transition between light and dark areas in a painting. It is often achieved by blending colors together or by using a soft brush to create a smooth, hazy effect.

Leonardo da Vinci, Michelangelo, and Rembrandt are all known for their use of chiaroscuro, a technique that involves the use of strong contrasts between light and dark to create a sense of depth and drama in their paintings.

Complementary colors are colors that are opposite each other on the color wheel, such as red and green or blue and orange. When used together, they create a sense of visual interest and excitement because they are highly contrasting.

Shape contrast is not a common type of contrast in art. Value contrast, color contrast, and texture contrast are all more commonly used to create visual interest and excitement in a composition.

Chiaroscuro is the term used to describe the use of light and shadow to create a sense of depth and dimension in a painting. It is often achieved by using strong contrasts between light and dark areas.

Vincent van Gogh, Henri Matisse, and Pablo Picasso are all known for their use of complementary colors. They often used these colors to create a sense of visual interest and excitement in their paintings.

Stippling is the term used to describe the use of dots or small strokes to create a sense of texture or shading in a painting. It is often used to create a soft, delicate effect.

Using different shapes and sizes is not a common technique for creating contrast in art. Using complementary colors, using light and shadow, and using different textures are all more commonly used to create visual interest and excitement in a composition.

Impasto is the term used to describe the use of thick layers of paint to create a sense of texture in a painting. It is often used to create a sense of depth and drama.

Georges Seurat is known for his use of stippling, a technique that involves using dots or small strokes to create a sense of texture or shading in a painting. He is considered to be the founder of the Pointillism movement.

Texture contrast is the term used to describe the use of different textures to create a sense of visual interest and excitement in a painting. It can be achieved by using different types of paint, by applying paint in different ways, or by using different materials in the composition.

Vincent van Gogh, Claude Monet, and Paul Cézanne are all known for their use of texture contrast. They often used different types of paint, applied paint in different ways, or used different materials in their compositions to create a sense of visual interest and excitement.

Shape contrast is the term used to describe the use of different shapes and sizes to create a sense of visual interest and excitement in a painting. It can be achieved by using different types of shapes, by using different sizes of shapes, or by using shapes in different ways.