Joku is the name for matting used for several purposes, including spreading on a desk to put the donated treasures on. As some sumi-ink inscriptions, such as hanadukue-joku (joku for desks for sutras and other Buddhist altar equipments), kyoudai joku (joku for sutra stands) and kouza (seat for lecturers), indicate, joku-s were sometimes made for desks, and sometimes for persons to sit on. Those joku-s use different materials for the filling according to the purposes. Those made to spread on objects, e.g., desks, use the woven mat(s) of soft rush or hemp cloth as the filling material. Colorful Japanese brocade is usually used as the front-side cloth, but there are some cases where fabrics with a twill weave are used instead. Dyed fabrics such as kyoukechi (textiles dyed by carved block resist) are also sometimes used. In many cases, koukechi (textiles dyed by bound resist) plain silk is used for the backside. The shape is usually rectangular, but there are also square and round ones. In Shosoin, there is an octagonal one made to fit the shape of the stand for donated treasures. Among these joku with different shapes, rectangular, square, round, and others, there are some with another characteristic; they have a frame made with another piece of cloth around the matting.
Of this joku, the brocade of the front side, the hemp cloth of the filling, and the koukechi plain silk with meyui-mon (white-dotted pattern) used as the back-side cloth are stored separately. The front part exhibits a grape arabesque pattern with two-color brocade, a kind of brocade that has one color each for the background and the pattern. Around the flower pattern with quatrefoils placed on top of one another, the leaves or the bunches of grapes at the tip of thin vines, and the coiled tendrils are laid out. From the sumi-ink signature left on the hemp filling, it is known that this joku is made with the choufu (cloth submitted as tax) from a person called Ohtomobe-no-Hitsuji in Shida-gun of Hitachin country, in Tenpyou Shouhou 6 (754). This joku is valuable in giving us such detailed information. There is also a piece of choufu, stored in Horyuji, that has a signature of Ohtomobe-no-Nakamaro, who was from the same area as Ohtomobe-no-Hitsuji.