A man with a grey beard and mustache sits turned slightly to his right, his gaze meeting the viewer directly. He wears a dark fur-lined robe, its rich brown and gold textures rendered with soft, layered brushstrokes that catch the light along the collar and sleeves. A translucent, pleated ruff encircles his neck, its crisp folds painted with delicate highlights and shadows that emphasize its airy volume.

On his head sits a dark, plush hat with ear flaps, its surface thick and velvety, contrasting with the smoothness of his skin and the sheen of his robe. The background is a muted, warm grey, fading into shadow and leaving the figure illuminated by a soft, directional light that models his features and costume in three dimensions. The composition is tightly focused on the sitter, with his upper body filling most of the panel and the light drawing attention to his face and hands.

Fine details, such as the texture of the fur, the glint on the ruff, and the veins on his hands, reveal the artist's close observation and technical skill. His left hand rests on the top edge of a red chair adorned with brass studs, which appears in the lower left corner of the painting. The background is smooth and featureless, transitioning from a lighter grey near the figure’s head to a darker tone at the upper edges and corners.

The light source falls from the left, casting subtle shadows on the sitter’s right cheek and under his hat’s brim. A faint highlight runs along the sitter’s left sleeve, accentuating the glossy, almost leathery texture of the black fabric. The fur trim on the robe is painted with loose, feathery brushstrokes that create a tactile softness along the edges.

There are no secondary figures or objects besides the chair and the paper, emphasizing the solitary presence of the sitter. The lower right corner of the painting is enveloped in deep shadow, blending the edge of the robe into the background. Portrait of Nicolaes Ruts is an example of Dutch Golden Age painting, marked by its attention to individual character and mastery of light and texture.