Pillows ,as is familiarly known ,were also hard ,and through the centuries every possible material was used .Some were of porcelain ,to be filled with hot water in winter or ice in summer ; but varieties in flexible strips of polished bamboo or of lacquered leather ,or also of finely woven rattan ,hollow and stretched on a framework ,were common .Peasants and unpretentious people ,even today ,in the North generally use dark blue cloth with a stuffing of various kinds of chaff and a shape square in cross section .Even collapsible pillows of jointed wood exist for the wayfarer .All of them ,however ,are to give fairly high ,firm support to the neck rather than to cushion the head .