Inlay. It is also written 象眼 (elephant eye). A decoration technique in which the surface of such materials as metal, pottery, and wood is carved and filled with metal, stone, shell, ivory, or horn. Inlay has been used on swords since the Kofun period, and on celadon ceramics since the 10th century. Inlay variants include: *mokuga 木画 and *raden 螺鈿. In dyeing and weaving, there is kirihame zōgan 切嵌象嵌 (openwork inlay). Techniques include: itozōgan 糸象嵌 (thread inlay), also called senzōgan 線象嵌 (line inlay), the simplest and oldest procedure in which a thread-like metal is set in carved patterns; hirazōgan 平象嵌 (flat inlay) in which flat sheets are inlaid to be the same height with the ground surface; takaniku zōgan 高肉象嵌 (high mounted inlay), used for swords, where material is set on a high-relief metal ground; nunome zōgan 布目象嵌 (texture inlay) in which gold or silver in wire or thin sheets is hammered into a finely-carved pattern; kirihame zōgan, a method of inlaying metal in an openwork design on a base metal so the same pattern can be seen from either side; and tokashikomi zōgan 銷込象嵌 (rubbed in inlay), in which the shallow-carved surface of metal is rubbed with gold leaf. These techniques are used for decoration of butsugu 仏具 (Buddhist altar fittings), furniture, arms, and swords.