An oil sketch or oil study is an artwork made primarily in oil paint in preparation for a larger, finished work. Originally these were created as preparatory studies or modelli, especially so as to gain approval for the design of a larger commissioned painting. They were also used as designs for specialists in other media, such as printmaking or tapestry, to follow. Later they were produced as independent works, often with no thought of being expanded into a full-size painting.
The usual medium for modelli was the drawing, but an oil sketch, even if done in a limited range of colours, could better suggest the tone of the projected work. It is also possible to more fully convey the flow and energy of a composition in paint. For a painter with exceptional technique, the production of an oil sketch may be as rapid as that of a drawing, and many practitioners had superb brush skills. In its rapidity of execution the oil sketch may be used not only to express movement and transient effects of light and color, its gestural nature may even represent a mimetic parallel to the action of the subject.