The Woman and Tambourine (Liber Studiorum, part I, plate 3), Joseph Mallord William Turner and Charles Turner, etching and mezzotint, roughly 7 x 11″ (21 x 29 cm). In the collection of the Metropolitan Museum of Art

This was one of the prints Turner created for a 70 plate “book of studies”, he published in the early 19th century.

It was the practice of many artists at the time to work with printmaking specialists, for whom they would create drawings or watercolors as guidelines.

In this case, JMW Turner made brown watercolors as a guide for tone, and etched the basic drawing into the plate himself, turning to frequent collaborator Charles Turner (no relation) to create the tones in mezzotint. (There is a nice short description of the mezzotint process here.)