Matériaux
Gypsum plaster; colourless glass; coloured glass (green, blue, yellow); red flashed glass
Technique
The window was made according to the traditional technique used in the manufacture of qamarīyāt in North Africa until today. Firstly, the rectangular stucco panel was produced by pouring gypsum plaster into a wooden frame. The average thickness of the stucco is c.30mm. Once the stucco had set, the latticework was carved out with sharp, knife-like tools. Then the openings were then covered with pieces of colourless and coloured sheet glass, which were fixed on the back of the lattice with a thin layer of gypsum plaster.
The design of the latticework has two levels. The main motif (level 0) is worked out in relief against the perforated background (level –1), which lies 5–10mm below level 0. The irregularly spaced, slightly conical perforations were pierced with a metal or wooden pin before the stucco was fully set. They are c.10mm in diameter. The distance between the holes is 7–10mm. All holes are backed with colourless glass. The main design and the perforations have been worked in such a way that the incident light is directed slightly downwards into the room.
The glass is either colourless or coloured in the mass. Small, elongated and parallel bubbles indicate that the glass sheets were mouth-blown, possibly using the broad-sheet method. The glass pieces were cut according to the design of the latticework. Scratch marks along the edges of some glass pieces testify to the use of a glass-cutter.
Etat de conservation et restaurations
This stucco and glass window is in good condition. The plaster lattice is intact, and the glass does not show any losses or defects.
Since its acquistion by the Institut du monde arabe in 2009, the window has not been restored. There are, however, signs of earlier repairs on the front: small losses were filled with plaster whiter and finer than that of the stucco lattice. There are no signs of restoration on the back, as the stucco layer used for embedding the pieces of glass looks uniform.