Glazes can be classified into two categories, depending on their melting temperatures. Low-fire glazes melt at temperatures below 900°C (1652°F), while high-fire glazes melt at temperatures above 1200°C (2192°F). Glazing technology had entered Japan as early as the seventh century, with the first glazed ceramics in Japan being covered in low-fire glaze made with lead. The most representative of these, however, were tri-color glazed works from the Nara period (8th century). Some of the earliest examples include green-glazed tiles from Kawara Temple in Nara, and a green-glazed coffin from the Tsukamawari tumulus.
During the Nara period, the Japanese ceramists were heavily influenced by the arrival of tri-color glazed ceramics from Tang China, and sought to produce their own. Initially, they decorated their ceramics in green, brown, and white, but slowly reduced them to green and white, before eventually settling on producing monochrome green-glazed products. By the subsequent Heian period (8th–12th century), polychrome glazed ceramics all but faded into obscurity, and ceramists used green glazes alone to mimic the celadon products from the Yuezhou kilns in China.
This four-legged jar, too, was modeled after a Yuezhou celadon work. This work, like others created in the Sanage kiln, was made larger than the originals they were based on. In fact, the gentle curves of Sanage jars are more reminiscent of Tang tri-colored ceramics than Nara tri-colored ceramics, which, although intended as imitations of their Tang cousins, often bore bold forms more closely resembling pre-Nara-period Japanese sue-ware jars. In addition to glazed decorations, this jar has three applied belts encircling its body, which intersect with four applied vertical bands that connect to the beast-like feet supporting it. The lucent green of the glaze covering the jar’s white body speaks to the Sanage kiln ceramists’ mastery of green-glazing techniques.
There are known instances of green-glazed four-legged jars being used as funerary urns, which makes it likely that this jar was also used as one.