Why is Pierre-Auguste Renoir’s work from 1883 to 1884 called the Ingres period?

Pierre-Auguste Renoir’s work from 1883 to 1884 is referred to as his "Ingres" period because it reflects a significant shift toward the Classicism associated with the French painter Jean-Auguste-Dominique Ingres.1

Following a period of doubt regarding Impressionism, Renoir traveled to Italy, where he was deeply influenced by the works of Raphael and the technical hallmarks of Classicism. Consequently, he began to prioritize the beauty of drawing, the purity of clear lines, and the expressive force of smooth painting to enhance the modeling of the human body.1

Because these works emphasized volume, form, and contours over his previous focus on color and spontaneous brushstrokes, art historians labeled this phase the "Ingres" period—or sometimes the "harsh" or "dry" period—to signify the stylistic similarity to Ingres’s disciplined techniques.1