Why did Mary Cassatt begin using pastels in her art?

Mary Cassatt began using pastels in her art to achieve a more intimate and vibrant quality in her work. The medium allowed her to create softer edges and delicate tones, which complemented her focus on themes of motherhood and the female experience. Pastels also provided her with the flexibility to work quickly and capture the spontaneity of her subjects, aligning with her Impressionist style. Ultimately, this choice enhanced her ability to express emotion and nuance in her paintings.