Panel painting becomes more common during the Romanesque period, under the heavy influence of Byzantine icons. Towards the middle of the 13th century, Medieval art and Gothic painting became more realistic, with the beginnings of interest in the depiction of volume and perspective in Italy with Cimabue and then his pupil Giotto. From Giotto on, the treatment of composition by the best painters also became much more free and innovative. They are considered to be the two great medieval masters of painting in western culture. Cimabue, within the Byzantine tradition, used a more realistic and dramatic approach to his art. His pupil, Giotto, took these innovations to a higher level which in turn set the foundations for the western painting tradition. Both artists were pioneers in the move towards naturalism.