A masterpiece of bronze-casting technology, this vessel, based on a conventional square container, is transformed into an inspired organic form by the ram at each corner. Their heads emerge as fully three-dimensional sculptures, while their chests and front legs appear in relief. Rendered with astonishing realism amid a dense sea of zoomorphic motifs, spirals, and scroll patterns, these complex shapes exemplify the characteristically elegant Shang fusion of abstract and representational animal motifs. Flanges are a purely abstract ornament, but here, running under the rams' chins and down their chests, they also serve as the rams' beards and woolly pelts. Incised birds with tall, scrolled crests cover the rams' bodies, while three-dimensional horned dragons project outward from either side of the ram's heads.
Large bronzes such as this massive square cauldron must have been among the most ambitious castings of the time. Only the elite were entitled to perform the rituals in which these vessels were used, and only the elite could afford to commission such vessels. The decoration on this massive vessel is simple and lies close to the vessel surface, and the animal frieze is in "thread relief"-thin lines created by incising the clay piece-mold with a pointed instrument. The great potential of the piece-mold technique was only beginning to be exploited.
The archaeological discoveries at Sanxingdui, where this enormous mask was found in 1986, are among the most remarkable in recent times. This site yielded elephant tusks, jades, gold sculptures, pottery vessels, awesome life-size bronze figures, and huge, grotesque bronze masks. All these artifacts, found in vast numbers in two sacrificial pits outside the remains of a large walled city, tell us that Sanxingdui was a major center of an early Bronze Age culture in far western China. Three masks, of which this is the largest, share the astounding feature of stalklike pupils protruding some six inches from the eyeballs. An ornamental projection may have originally been attached to the rectangular hole between the two eyes. The two holes on either side of the mask, next to the ears, may have been used to fasten the mask to a central core made of a perishable material such as wood or packed clay.

The form and size of these masks are unparalleled and their use is unknown. Nothing similar has ever been found in any other Chinese Bronze Age site. However, the effort and cost of casting them must have been justified by their ritual or spiritual significance to those who made and buried them. Discoveries such as this mask have created great surprises in the archaeological field and have initiated new directions in research, including the reexamination of ancient texts. References in these texts to a mythical people from a territory called Gushu, whose ancestors the Cancong  had protruding or bulging eyes, take on new meaning with the discoveries at Sanxingdui.