To decorate the Lefuel staircase in the Richelieu wing, the Louvre commissioned a window installation from François Morellet, an internationally renowned artist with a passion for abstraction since the 1950s. The monumental double flight of stairs is bathed in the light of multiple bay windows that open onto both the exterior and the interior of the museum. The luminosity there is striking. With lightness and elegance, François Morellet redesigned the bay windows and oculi. He says himself that he "enjoyed fragmenting and destabilizing the panes of glass with their rather inelegant ironwork, and confronting them with their own image, created using an old and invaluable technique of the master glassworkers." The process of superimposing geometric grids is a characteristic of François Morellet's entire approach; here, the reversed design of the grid fits into the old outline. The decor installed in late 2009 makes use of all of Morellet's artistic qualities: a perfect match with the architectural program and the commission, precision and balance of presentation, subtlety of the formal motif, play of the mind, clarity and visual intelligence.