The ceiling, made of painted wood, consists of two rows of central coffers, with concave lobes, flanked by small square or star-shaped coffers; the system is made of alveoli and muqarnas, typical of Islamic architecture. In particular, the central aisle is decorated with muqarnas, which form the geometric structural base, starry polygons and small domes, the latter made of thin boards. In the side aisles, long panels of sloping rafters form a coffered ceiling with alternating flat and concave bands.
The specialised workers excelled in woodworking, as each element of various shapes and sizes is cut, assembled and worked according to a precise order and technique, demonstrating an extensive knowledge of the physical and mechanical characteristics of the materials used. In fact, the interlocking of the elements that form a stable, self-supporting and balanced mechanism is skilful. The wood used in the ceiling ranges from fir, black pine, poplar and beech. It’s like you can still smell the scent of freshly cut fir trees. It could be a Sicilian type: the Abies nebrodensis.
The ceiling of the Palatine Chapel is characterised by muqarnas, an ornamental decoration typical of Islamic architecture and most commonly found in the vaults of buildings. The interplay of joints and volumes creates an evocative composition, which one would like to be able to caress in order to appreciate its plastic forms.