This jar bears three levels of transverse parallel lines enclosing the form from the shoulder to the trunk, hence the name sankinko (pot with three lines). Sankinko were fired frequently in the late Heian period. They have been found in many Esoteric Buddhist temples and sutra mounds, suggesting their deep significance for religious activities during the Heian period. At the beginning of the Kamakura period, however, production of sankinko quickly ceased.