The Swiss landscape continued to inspire artists long after Calame. While some painters like Johann Gottfried Steffan (1815–1905) emulated Calame in subject, style, and technique, the academic tradition was challenged as early as 1845 by Barthélemy Menn (1815–1893), whose expressive technique favored paintings that were less polished. In the later years of the nineteenth century, most Swiss artists sought a balance between the academic tradition and the new interest in open-air painting inspired by French painters such as Camille Corot and Théodore Rousseau. Rudolph Koller (1828–1905), for example, produced outdoor sketches for sale, but not before varnishing them to make them seem more finished.