A modello, from Italian, is a preparatory study or model, usually at a smaller scale, for a work of art or architecture, especially one produced for the approval of the commissioning patron. The term gained currency in art circles in Tuscany in the fourteenth century. Modern definitions in reference works vary somewhat. Alternative and overlapping terms are "oil sketch" (schizzo) and "cartoon" for paintings, tapestry, or stained glass, maquette, plastico or bozzetto for sculpture or architecture, or architectural model.

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.