What is the purpose of underpainting in the painting process?

Underpainting serves as an essential foundational layer in the painting process, primarily involving the application of a base color, which is often monochromatic. This stage establishes a value structure and allows the artist to map out the major shapes and forms of the composition. By using a single color or limited palette, it helps to unify the subsequent layers of paint and can enhance the overall depth and luminosity of the final artwork.

This technique provides a guide for subsequent layers, ensuring that light and shadow are accurately represented. Additionally, since the underpainting is typically dry when later layers are added, it prevents muddying of colors, allowing for greater clarity and vibrancy in the finished piece. Ultimately, underpainting is a strategic step that supports the overall composition and enriches the visual impact of the painting.