In Madame Gautreau (Madame X), John Singer Sargent presents a striking portrait of a woman in a black gown. The figure stands against a dark background, which enhances her pale skin and the sheen of her dress. The composition is elegant, with the subject's posture conveying both confidence and vulnerability.

The use of color is bold, with deep blacks and soft whites creating a dramatic contrast. The painting is executed in oil on canvas, measuring 91.4 x 132.1 cm. Sargent's brushwork is meticulous, capturing the texture of the fabric and the delicate features of Madame Gautreau. The attention to detail is evident in the way light interacts with her gown and skin.

This realism is characteristic of Sargent's style, emphasizing both beauty and individuality. John Singer Sargent was an American artist known for his portraits of high society. Madame Gautreau was initially controversial due to the subject's pose and attire, leading to mixed reactions at its debut. Interestingly, the painting's title was later changed to avoid scandal, and it became one of Sargent's most famous works.

Today, it is housed in the Museum of Fine Arts Boston, where it continues to captivate viewers.