Which technique involves scratching through a layer of paint to expose what lies beneath?

The technique that involves scratching through a layer of paint to expose what lies beneath is known as sgraffito. This method is traditionally used in various artistic practices, particularly in painting and ceramics. It allows an artist to create intricate designs by removing the top layer of color to reveal the contrasting color or surface underneath. Sgraffito can add texture and visual interest to a work, making it a favored technique for adding depth and detail.

The other techniques mentioned have different applications. Wet on wet involves blending paints while they are still wet, creating soft edges and a more fluid appearance. Drybrush refers to a painting method where a dry brush is used to create a scratchy, textured effect on a surface, but it does not involve removing paint layers. Impasto is characterized by the application of thick layers of paint that create a three-dimensional effect but does not include scratching through layers. Understanding these distinctions highlights the unique qualities and uses of sgraffito in art.