Tilework, particularly in the form of mosaic tilework called "zellij", was a standard decorative element along lower walls and for the paving of floors. It consisted of hand-cut pieces of faience in different colours fitted together to form elaborate geometric motifs, often based on radiating star patterns. Zellij made its appearance in the region during the 10th century and became widespread by the 14th century during the Marinid period. It may have been inspired or derived from Byzantine mosaics and then adapted by Muslim craftsmen for faience tiles. The tiles are first fabricated in glazed squares, typically 10 cm per side, then cut by hand into a variety of pre-established shapes (usually memorized by heart) necessary to form the overall pattern. This pre-established repertoire of shapes combined to generate a variety of complex patterns is also known as the "hasba" method. Although the exact patterns vary from case to case, the underlying principles have been constant for centuries and Moroccan craftsmen are still adept at making them today.