later gold becomes standard, and if the entire background is not gold leaf, the halo itself usually will be. Decline of the halo With increasing realism in painting, the halo came to be a problem for artists. So long as they continued to use the old compositional formulae which had been worked out to accommodate haloes, the problems were manageable, but as Western artists sought more flexibility in composition, this ceased to be the case. In free-standing medieval sculpture, the halo was already shown as a flat disk above or behind the head. When perspective came to be considered essential, painters also changed the halo from an aura surrounding the head, always depicted as though seen full-on, to a flat golden disk or ring that appeared in perspective, floating above the heads of the saints, or vertically behind, sometimes transparent. This can be seen first in Giotto, who still gives Christ the cruciform halo which began to be phased out by his successors. In northern Europe the radiant halo, made up of rays like a sunburst, came into fashion in French painting around the end of the 14th century. In the early 15th century Jan van Eyck and Robert Campin largely abandoned their use, although some other Early Netherlandish artists continued to use them. In Italy at around the same time, Pisanello used them if they did not clash with one of the enormous hats he liked to paint. Generally they lasted longer in Italy, although often reduced to a thin gold band depicting the outer edge of the nimbus, usual for example in Giovanni Bellini. Christ began to be shown with a plain halo. Fra Angelico, himself a monk, was a conservative as far as haloes are concerned, and some of his paintings demonstrate the problems well, as in several of his more crowded compositions, where they are shown as solid gold disks on the same plane as the picture surface, it becomes difficult to prevent them obstructing other figures. At the same time they were useful in crowded narrative scenes for distinguishing the main, identifiable, figures from the mass of a crowd. Giotto's Lamentation of Christ from the Scrovegni Chapel has eight figures with haloes and ten without, to whom the viewer knows they are not meant to attach a specific identity. In the same way, a Baptism of Christ by Perugino in Vienna gives neither Christ nor