"I am cautiously optimistic based on my extensive research and the provenance linking it to the esteemed Madeira family of Philadelphia ... is thought to be a portrait of Renoir's wife Aline ...

Etched into the piece appears to be the name "Renoir." The label also suggests the former owner of the sketch previously donated it to the Philadelphia Museum of Art. Markow tells PEOPLE that the ...

Renoir’s later portraits make little attempt to analyze the sitter’s personality. What most interested him was technique—specifically that of Rubens, whose skill with pigments he had admired.

Markow believes that it is a drawing dating to the late 1800s and is a portrait of Renoir’s wife, Aliene Charigot during his Ingres period and a time when “he paid a lot of attention to light ...