underpainting

Underpainting is a painting technique in which an initial layer of paint is laid down to establish composition, tonal values, and the distribution of light and shadow before the final colors are added. This foundational layer helps guide subsequent painting and can influence the overall balance and luminosity of the work. Underpainting is often monochrome or toned in earth colors, a practice known as grisaille, though tonal or color underpaintings are also common. In Italian practice, a thin wash applied to the primed ground is called imprimatura, aimed at reducing the canvas’s stark whiteness and setting a tonal baseline.

In oil painting, the underpainting defines forms and value relationships, serving as a map for later color work. A typical sequence starts with a drawing or block-in to establish composition, followed by a tonal underpainting (grisaille or a limited palette). Once dried, transparent or semi-opaque glazes are applied to build color depth while preserving the underlying value structure. The underpainting can be opaque or transparent, and glazes can alter hue and temperature without erasing the tonal groundwork.

Historically, underpainting has been central to many Old Master practices, notably among Renaissance and Baroque painters, including Rembrandt and Velázquez, who used it to achieve depth through layering and chiaroscuro. In modern practice, underpainting remains common in oil painting and can be employed in acrylic or mixed-media workflows as a preparatory step. It is valued for solving composition and lighting issues early, improving cohesion, and guiding color harmony in the completed work.