Polymath Constantijn Huygens (1596–1687) once estimated that he must have written and received approximately 100,000 letters. Of these around 10,000 have been preserved, addressed to and sent from 1,300 different correspondents, of whom more than hundred were international artists. As secretary to the Dutch Stadholders, Huygens frequently functioned as an intermediary between the house of Orange-Nassau and artists. By analyzing his correspondence with painters such as Rembrandt, Van Campen, Bosschaert, Hanneman, Seegers, and Honthorst, this paper examines the visualization of the ideas and wishes of Huygens and his employers. In addition, it will also examine the mode of communication regarding the progress, delivery and payment of the works. Finally, this paper will Huygens' agency in mediation between artist and patron.