Why did Edgar Degas create related series of drawings and pastels?

Edgar Degas created related series of drawings and pastels as a way to engage in deeply challenging artistic exercises that moved beyond simple subject matter. By experimenting with charcoal drawings on tracing paper and retracing them multiple times before adding pastel, he was able to produce a "family" of related compositions.1

This process allowed Degas to manipulate the finest nuances of gesture and detail while elevating the fundamental elements of picture-making—specifically color, form, and composition—to a newly independent level. These sequences functioned similarly to the series paintings of Claude Monet, providing a structured method for the artist to explore and refine his creative vision.1