A Lady sitting by a Fountain, possibly Catharina Dierquens

Maes's Lady Sitting by a Fountain from around 1685 shows his late portrait style—influenced by Flemish Baroque portraiture, especially the work of Van Dyck as filtered through the Amsterdam fashion of the 1670s and 1680s—fully established as his dominant mode. By this date Maes had largely abandoned the intimate Rembrandtesque genre scenes that had made his early reputation in favor of grand, fashionable portraits that satisfied Amsterdam's wealthy merchant class desire for images in the international manner. The outdoor garden or fountain setting, with its suggestion of aristocratic leisure and grand estate, was a compositional convention borrowed from Van Dyck's portraiture that gave Dutch subjects a European courtly prestige. The painting demonstrates how completely Maes transformed his artistic identity over three decades in response to changing patron taste.

The garden setting adds decorative richness to the portrait, with the fountain providing a secondary focal point. Maes's smooth, polished late technique renders the sitter's costume and the surrounding elements with equal refinement.