Plaster was also used on the brick walls, which were faced with a hard coat about a tenth to a sixteenth of an inch thick, upon which paintings were executed. By the XVIIIth dynasty this became a mere whitewash over the mud-facing of the wall. In the roughly-hewn rock tombs of that age at Thebes, the jagged surfaces were smoothed by a coat of plaster, often two or three inches thick in the hollows. A strange use of stucco was for a thin coat over sculpture, as a basis for colouring. Such a coat was even laid over statuary. In all ages this hid to some extent the full detail of the sculptor’s work in reliefs. In the XIIth dynasty the finest lines were hidden by it; and on coming down to the Ptolemaic times the plasterer ignored all the sculpture below, filling the figures with a smooth daub of plaster on which the painter drew what he liked. It seems strange why the sculptors should have continued to put fine work and detail on to a surface where they were going to be at once ignored. It suggests a rigid bureaucracy in which the sculpture had to be passed by one man, and the painting by another, without any collaboration. Stucco was used for independent modelling, as in Italy. It was laid on a flat canvas base, stretched over wood, and the whole relief was in the stucco. The chariot of Tahutmes IV is one of the main examples of such work, of which a small portion is shown in fig. 132. The relief is low and smooth, and full of detail; there is none of the sketchy rough tooling, as seen in Roman stucco reliefs. Minute details of dress and hair are all tooled in, and supply some of the best studies of Syrian robes. The varying patterns on the shields of different branches of Syrians, the feathering of the arrows, the shape of the daggers, and the flowers of the papyrus and lotus of north and south, are all most precisely rendered. It would be hard to find any point in which more details could be introduced. [Illustration: PLASTER 132. Stucco relief modelling (XVIIIth dynasty) 133, 134. Plaster castings for studies]