Bronzes mark the beginning of civilization in ancient China. They epitomize the nobles' reverence for rites. Bronzes are called "ritual vessels", as they served as ceremonial offerings for gods or ancestors, official gifts for a mutual exchange, or utensils at banquets. Nobilities, according to their ranks, were entitled to possess bronzes of various types and sizes. Bronzes were an indispensable tool to consolidate the reign. They were a symbol of power.
Looking back into the history, bronzes of the Xia, Shang and Zhou dynasties were admired for their myriad forms, intricate patterns, and superb casting techniques. They reflect the breadth and profundity of Chinese culture and the marvellous creativity of ancient Chinese. In the Qin and Han dynasties, the popularity of bronzes declined. Later in the Song, Yuan, Ming, and Qing dynasties, the bronze art reappeared with archaism. Bronzes from the remote and border areas were distinctive in shape and style. These precious artifacts help to understand the cultural profile and mutual integration of ancient ethnic minorities in China. They have also witnessed the development of plural and integrated pattern of Chinese civilization.
This broad-axe is thick and solid, inlaid with delicate and beautiful decorations which are very well preserved. There are two rectangular holes on the body for leather straps to pass through to fix wooden handle.
Yue is a long-handled arc-bladed hacking weapon, as well as an instrument of torture. This function was clearly manifested in the pictographic characters of head-chopping on the inscriptions of bronzes. However, some Yue like this large and heavy broad-axe, with flat end and edgeless blade, without any trace of use, are assumed to be for ritual use only. This kind of Yue is generally found in tombs along with other exquisite funerary objects, as a symbol of monarchical or military power.
Jia is a wine vessel used for sacrificial rituals. From the traces of soot on the outer base and the white watermark in the belly, it can be deduced that it is also a vessel used to heat wine. Bronze Jia appeared in the late Xia and its shape matured by the mid-Shang. In the mid-Shang dynasty, they usually had a flat bottom, so a pouch-shaped like this was quite uncommon.
The surface of the vessel is decorated with animal-mask motif with dense and exaggerated lines, showing a mysterious and dignified style. It is the only piece with such decoration among the existing bronze Jia of the mid-Shang dynasty.
The pattern of this pot is similar to the lines on the pottery of the Longshan Culture and those on the jade deity's head of the Liangzhu Culture, very likely to be a non-realistic. Pots of the same shape have been unearthed in the Central Plains region, usually with a loop handle. The two rings can be threaded with a rope, which has a similar function as a loop handle. Bronze vessels prior to the mid-Shang have not yet been found with specific inscriptions. But on the inside wall of the ring foot of this pot is cast with a character ‘X’, like a small cross, which should be the clan emblem. This is one of the earliest inscriptions on bronzes found so far.
Lei is a large wine vessel commonly seen in the late Shang and mid-Western Zhou dynasties. Bronze art saw its peak in the late Shang dynasty. This piece of work is imposing and dignified, exquisite and magnificent, standing out among all its kind. It is in six-layer high relief design from top to bottom against a background of fine and beautiful cloud and thunder pattern. The rim, the upper belly and the ring foot are decorated with bird-like designs, with symmetric dragon designs at the shoulders, a front beast head of big spiral horns in the middle, animal-mask motifs on the middle and lower parts of the belly and sharp clawed feet at the bottom. Some protruding parts like the horns and dragon tails are decorated with intaglio lines, showing a ferocious and mystical beauty. This is a typical ware of ‘three-section all-over pattern vessel’, representing the supreme level of bronze casting technology at its peak.
At the front of the Gong lid is the head of an imaginary animal, with a pair of giraffe's horns, a pair of rabbit's ears and glaring eyes. Behind each horn, there is a small snake. On the central ridge of the lid, there is a small dragon carved in relief, with a long body and a curled tail. On the rear end of the cover is carved an ox head with protruding horns, pricked ears and corked tongue, corresponding to the ox head handle. A large-sized phoenix pattern decorates the belly part, in regal and solemn air. Other phoenixes are decorated on the ring foot, the back of the big phoenix and lids and other parts, in different shapes and picturesque disorder. The vessel is exquisitely cast and decorated, giving strong mystical overtones.
Gong, a ritual wine vessel, comes in two forms. The whole vessel is either shaped like an animal, often an ox or ram, or the lid of the vessel is shaped as a mythical creature while the body is jug-shaped with a ring foot. This piece belongs to the second type. With no background pattern on the vessel, it was a new trend in the ornamentation of the bronzes of the late Shang dynasty.
Gu is a drinking vessel. This piece is exquisitely shaped and beautifully decorated, indicating extremely high casting technology and design level. The openwork carving at the ring foot is quite uncommon among Gu wares. The vessel is a treasure in bronze Gu of the Shang dynasty. It gains its name for the inscription in the foot ring Huang, the family name of the maker.
The mineralization of the whole vessel produced basic cupric carbonate, which made the surface of the ware shiny and green, beautiful and mysterious. The ram heads could be covered on the ornamentation on the shoulder, which implied that the heads were cast separately. The body of the vessel was case first, and then holes and passages were left on the shoulder and finally pottery model was built on the holes and passages to cast the ram heads. Such unique decorative composition is only found in early and middle Shang bronze wares, with an exception of the Yin Ruins, and the casting region remains a mystery to date.
This vessel gets its name from the four lines of 22 characters engraved on the base of the inner belly which records King Zhou commanding Duke Ming to make the expedition to the East, and rewarding Marquis Lu. It is plain and unadorned as a whole with nodular shape on the surface and concave-convex alternation, looking simple and modest.
It is distinctively shaped and unique of its kind. The bronze wares of the early Western Zhou inherited the animal-mask motif of the late Shang, with simpler decorations on some utensils. The Zun of Marquis Lu reflected this unique aesthetic appeal to the extreme and at the same time pioneered the simple style of the bronzes of the middle and late Western Zhou.
Gui, as a food vessel, had gradually become a major artefact in the bronze sacrificial wares after its advent in the early Shang. By the mid-Western Zhou, the use of Gui was gradually institutionalized. The number of vessels used was clearly regulated according to the rank of the user, usually in even numbers matched with Ding.
Bird-like patterns are often used to adorn the rims on the rectangular walls of the vessels of the late Shang and early Zhou, such as the belly part of square Ding and the stand of Gui.
The inscription of the only word Jia found in the inner base is the name of the owner. This is an example of the Zhou people marking with Heavenly Stems and Earthly Branches.
This small shaped Yi has a coiled trunk-shaped ear on each side of the belly. A middle wall is set inside to contain different kinds of wine in the two partitions. On one side below the lid there are two square gaps to place the wine ladle which is missing. Inside the body and on the lid, there are same six lines of inscription of 16 characters.
Yi is a wine vessel. Most of the square Yi in the Western Zhou have curved walls, but a few have ears or a middle wall. This square Yi with strange shape and exquisite design is a rare treasure.
Da Ke Ding was excavated in cellar of Famen Temple, Fufeng County, Shaanxi province in Guangxu reign period. There were some smaller Dings and chimes unearthed with it. It is the master treasure of the Shanghai Museum collection, also a widely cited and world-famous national treasure. With its majestic and stately shape, smooth and grand decoration, this Ding perfectly integrates the pictorial and sculptural art of that time. The traditional patterns and designs from the early Zhou changed completely and Da Ke Ding witnessed the transitional moment.
There is a long inscription of 28 lines of 290 characters inside the vessel whose content can be divided into two. The first is a eulogy from the Shanfu (an official position, similar to royal chef) Ke to his grandfather, Shi Hua Fu who assisted Zhou. The second records the rewards Ke received from the King Xiao of Zhou since he took his office. The inscriptions are in large, simple and regulated characters with powerful strokes and well-proportioned layout.
Pan is a water container used to contain the used water after ritual washing at sacrificial ceremonies and banquets during the Shang and Zhou periods. The ritual of washing by pouring water fell out of use in the Warring States Period. Pan gradually became a water container, also known as Xi (washer).
The interior is decorated with many aquatic animals, either in relief or three-dimension. With fish, turtle, frog, water bird all available, it is just like a scene in an aquarium. The most extraordinary feature is that all the round-carved animals can be swivelled in 360 degrees. When water pours into Pan, the fish, tortoise, frog and bird move in the water as if alive. It is an unprecedented wonderful creation. The casting workmanship is remarkable for its time, because it overcame the technical problem of the adhesion of moving parts, with the animal stems cast in the thin layer of the base, making them vertical without collision with each other when spinning.
An inscription of 32 characters is cast inside the Pan, meaning the master made this Pan for washing up for his wife, Zhong Jiang on the seventh of June on lunar calendar and it was large and wonderful.
Yi is a water container, often used together with Pan. Dragons represent water, so water containers or washing vessels are often decorated with dragons and aquatic animals. The decoration and styling of this Yi was typical in the late Western Zhou. But it is larger than its kind of the Western Zhou found so far, reflecting the noble status of its owner.
Four lines of inscriptions in 22 words were inscribed on the inner base of the Yi, indicating that it was a gift made for the first daughter of his wife Guojun by Marquis Qi. For political positions and protections of interests, the vassals of the Western Zhou often allied with each other. The Yi of Marquis Qi was a wedding gift to maintain the alliance.
Unearthed at the tomb of the Marquis of Jin, Beizhao Village, Quwo County, Shanxi province in 1992, this set of musical chimes with a total of 16 pieces, can be divided into two groups, with 8 pieces for each. Lining up according to size, these pieces can form two rows of chimes with harmonious scales and rhythms. With a total of 355 characters inscriptions carved, this is the first of its kind in the bronze inscription in the Western Zhou. The inscriptions record the time and merits of Marquis Su on his expedition with King Li of Zhou to the east which was unseen in the history books and an important supplement to the history materials of Western Zhou. In addition, the almanac of the Western Zhou can be deduced according to the inscriptions.
This piece of work is modelled like a water buffalo. The belly of the buffalo is hollow and there are three holes from its neck to the end of its back. Inside the middle one, there is a removable pot-shaped container. Judging from its structure, it is a wine-warming vessel. Hot water can be poured into the hollow belly to heat the wine in the pot-shaped container on the back. Modelling wine vessel Zun in animal shapes is a unique feature of Chinese bronzes.
The vessel looks dignified. The four legs are short but the two powerful horns and wide-open eyes retain the sense of reality, combining the artistic conception and utility harmoniously. The ring in the nose indicates that as early as in the Spring and Autumn period, domestication of cattle by piercing the nose had already begun. It is a valuable material object for the study of China's history of the domestication of livestock. It is finely decorated in shallow relief with animal faces composed of coiled dragon and snake patterns on the buffalo’s head, neck, body and legs. Reliefs of tigers and rhinoceros in vivid forms and beautiful workmanship are found around the neck of the buffalo and on the pot-shaped container.
The drum stand is a hemispheroid with ring-foot. The raised hollow cylinder in the centre is used to insert the drum column. Twelve intertwined circular engraved coiled dragons scramble on the hemispherical drum surface. The dragon head holding a ring in its mouth is carved in the round and the dragon bodies are of high relief. The eyes of the 12 dragons are round but hollow, which were likely inlaid but are missing now. As both ends of the dragon horns are empty slots, it is likely that similar decorations were also inlaid.
This work is a combination of the carving in the round, high relief, low relief and intaglio techniques and an integration of different craft process including separate casting, forging, copper brazing, pewter work, inlaying and so on. The dynamic shapes and symmetrical layout make up a three-dimensional sculpture where a group of dragons intertwine with each other with their heads rising and tails wagging. It is a model of the combination of casting and sculptural art.
As the back of the vessel is flat, it looks round from the front whereas flat from the side, the unique design of which makes it remarkable.
The earliest known Hu was made in the mid-Shang, remained in fashion until the Han dynasty. The basic shape and structure is in round or flat round, sometimes square or square-oval with a lid or rings on the shoulder, which can be used to thread a loop handle or a rope handle. Large-sized Hu began to prevail in the mid and late Western Zhou. Since its body was too large to carry with a handle, a pair of beast-head ears holding a loose ring was often fixed to the neck.
Dou is mainly used for pickles and meat paste, or rice. People began to use Dou in as early as the late Shang dynasty but this kind only became popular in the Spring and Autumn and the Warring States periods.
The copper inlaid decorations of the vessel are two sets of hunting scenes on the lid and the body. Among the fleeing animals, some hunters are either ready to shoot arrows, or cast spears, while others are stabbing swords. Groups of animals are running desperately and some of them are already shot with several arrows. The whole pattern vividly records the specific hunting situations of the ancient nobility, regarded as a masterpiece of bronze marquetry. Decorations of human figures only appeared in the late Spring and Autumn, depicting scenes including banqueting, archery, harvesting mulberry leaves, hunting, wrestling, besieging cities and water battles.
Bronze marquetry started from the late Spring and Autumn. Bronzes themed with hunting design were a new subject at that time. It was closer to nature and life by breaking from the patterned features and mysterious colour of previous bronze design. This was also a reflection of Chinese ancient painting art in bronzes.
The whole body of this vessel is covered with geometric designs, arranged in oblique crossing, with no fixed format. It is inlaid with silver and turquoise, which is rarely found intact.
Jian is a large water vessel. Based on evidence from historical records and archaeological findings, Jian had several functions: as a water vessel; a container for ice to keep food cold; and as a mirror before bronze mirrors became popular. People also used it for bathing. Jian appeared in mid-Spring and Autumn period and became popular in later of this period and during the subsequent Warring States period. The Western Han still saw its cast.
This piece of work has two horned dragons with coiled tails climbing up on the front and back of the vessel with the front claws and noses on the rim, looking very vivid and lively. The neck and belly of the vessel are decorated with interlaced dragon designs. The kind of tangled and spiral dragon design was a fashion in the Spring and Autumn and the Warring States periods. Inside the vessel, there are two lines inscribed with thirteen characters recording that Fu Chai, King of Wu selected the best bronze and had this Jian made for his own use.
Cowrie container is a special bronze ware of the Dian people of Yunnan area. It got its name because it contained money cowrie when unearthed, with eight yaks of different gestures on the cover. The vessel is shaped like a wasp-waisted cylinder with a big yak and seven small yaks cast on the cover. The big yak in the centre stands on the drum-shaped stool, with its long and curved horns raising forward, looking powerful and vigorous. Seven small yaks stand along the edge of the cover with their heads and tails drooping. Two tiger-shaped ears are cast on the waist of the vessel with imposing gesture and covetous eyes.
Unearthed at Lijiashan, Jiangchuan, Yunnan province, this relic is an iconic artefact reflecting the characteristics of Yunnan bronze culture. Yunnan bronze wares are often seen decorated with yak and tiger motifs.
Bronzes mark the beginning of civilization in ancient China. They epitomize the nobles' reverence for rites. Bronzes are called "ritual vessels", as they served as ceremonial offerings for gods or ancestors, official gifts for a mutual exchange, or utensils at banquets. Nobilities, according to their ranks, were entitled to possess bronzes of various types and sizes. Bronzes were an indispensable tool to consolidate the reign. They were a symbol of power.
Looking back into the history, bronzes of the Xia, Shang and Zhou dynasties were admired for their myriad forms, intricate patterns, and superb casting techniques. They reflect the breadth and profundity of Chinese culture and the marvellous creativity of ancient Chinese. In the Qin and Han dynasties, the popularity of bronzes declined. Later in the Song, Yuan, Ming, and Qing dynasties, the bronze art reappeared with archaism. Bronzes from the remote and border areas were distinctive in shape and style. These precious artifacts help to understand the cultural profile and mutual integration of ancient ethnic minorities in China. They have also witnessed the development of plural and integrated pattern of Chinese civilization.
(Xia, 21st – 16th century BCE)
Around the 21st century BCE, China entered the Bronze Age. Small bronzes were found in the Taosi site in Shanxi province and the Shimao site in Shaanxi province. In the Erlitou site in Yanshi, Henan province, archaeologists discovered bronze containers, musical instruments, weapons, tools, and ornaments, as well as sites of bronze casting foundries. The Erlitou Culture in the late period (18th-16th century BCE) of the Xia dynasty was comparatively a mature bronze culture in China.
In this period, the bronze vessels were evenly shaped with thin wall and decorated with simple designs. The piece-mold casting became sophisticated. Patterns of animal mask and turquoise inlays appeared. Bronzes possessed ritual value, marking the beginning of a civilized society in China.
(Early and Middle Shang, 16th – 13th century BCE)
This was a critical period for the evolvement of Chinese bronze art. The system of ritual vessels was established chiefly based on the use of wine vessels in combination. Bronze weapons increased in variety. The animal-mask motif decorated most of the bronzes in a dense and complex composition. The patterns were executed with bold, deeply cut linear elements. Inscriptions with one character began to appear. The application of separate casting became more proficient. Techniques of making and combining molds made considerable progress. Bronzes from this time have been unearthed along the Yellow and Yangtze rivers. The period laid the foundation for the prosperity of ancient Chinese bronze art.
(Late Shang and Early Western Zhou, 13th – 11th century BCE)
The period from the late Shang to the early Western Zhou witnessed the zenith of Chinese bronze art. In the Shang dynasty, the system of ritual vessels with an emphasis on drinking vessels reached perfection. Wine vessels achieved a rich variety and an appreciable quantity.
Animal motifs such as animal mask, dragon, and phoenix were unprecedentedly sophisticated. These imposing and vigorous patterns were delicately crafted in a mixed manner of relief, high relief and intaglio. Most bronzes bear inscriptions that identify families and ancestors. In the late Shang period, inscriptions recording events emerged. In the early Zhou, some ritual practices of the Shang dynasty remained, but the ritual system shifted the emphasis from drinks to food. In this period, inscriptions on bronzes grew longer.
(Middle Western Zhou, Late Western Zhou, Early Spring and Autumn, the end of 11th – the first half of 7th century BCE)
The period marked a turning point in the ancient Chinese bronze art. The system of food vessels as dominant ritual vessels became fully mature. Ensembles of ding vessels, zhong (chime bells) and water vessels appeared. This trend indicated significant changes in ritual practices and social norms. Animal mask patterns gave way to those stylized animal motifs crafted in a simple and spontaneous style. Inscriptions were increasingly common on bronzes. Many important vessels bear long inscriptions. In the early Spring and Autumn period, the bronze forms and motifs inherited from those in the mid-to-late Western Zhou.
The vassal states established their own bronze casting industries, but their production qualities varied from state to state.
(Middle Spring and Autumn Period, Late Spring and Autumn Period, Warring States Period, the first half of 7th century – 221 BCE)
From the middle Spring and Autumn period to the Warring States period, the Chinese bronze art enjoyed a second flowering. The bronzes made in vassal states developed towards maturity with distinctive regional characteristics. Regional bronzes complemented each other, including those made in states of Qin, Jin, Qi, Lu, Yan in the Central Plains, the State of Chu in the south, states of Wu and Yue in the southeast, Ba and Shu in the southwest and the northern steppe. Bronzes tended to be more practical. The ritual function declined. Intricate patterns and innovative designs appeared more than before.
Dragon-themed motifs were crafted in a detailed and dense manner. Scenes of human activities emerged as the main motif for the first time. Characters in inscriptions focused on aesthetic appeal. The methods of lost-wax and pattern blocks were applied in the casting process. Delicate inlays showcased superb craftsmanship in this period.
(Qin till the Five Dynasties, 221 BCE – 961 BCE)
This period saw the decline and fusion of Chinese bronze art. During the Qin and Han dynasties (221 BCE-220 CE), the ritual significance of bronzes faded. Simple craftsmanship and plain aesthetics went popular. Bronzes were more functional. During the Western Han (206 BCE-8 CE), the wide use of iron tools made it easier to incise patterns on bronzes. It became popular to decorate bronzes with incisions. Techniques such as gold and silver inlays, gilding, and painted designs exuded immense charm. At the same time, in the south western region, the bronzes of the Dian culture reached their peak. During the Wei, Jin, Northern and Southern dynasties (220-589), the process of cultural integration among various ethnic groups accelerated. The traditional cultural values of bronzes changed greatly. In the Sui (581-618) and Tang (618-907) dynasties, frequent cultural exchanges between China and foreign regions introduced exotic features into daily wares.
(Northern Song till Middle Qing dynasty, 960-1840)
During the Northern Song dynasty (960-1127), the ruling class, facing political reforms, endeavoured to reshape rite system and establish a new hierarchy of rites and laws. As more bronzes from the Xia, Shang, and Zhou dynasties had been unearthed, a nostalgic sentiment grew in the imperial court and among literati, longing for the culture in the three ancient dynasties. After Emperor Huizong established rules of rites and music, new ritual significance was attached to the bronze art. In the Yuan (1271-1368), Ming (1368-1644), and Qing (1644-1911) dynasties, as the ruling class prized Neo-Confucianism proposed by Zhu Xi (1130-1200), ritual vessels cast for Confucius schools and ancestral temples followed the styles of those from the Northern Song dynasty. Such practice of ritual bronzes also impacted the entire East Asia.
Bronze is one of the earliest alloys smelted by humans. The mastery of bronze production indicates how advanced a civilization is. The earliest known bronze casting site in China is the Erlitou bronze casting foundry (17th-16th century BCE), located in Yanshi, Henan province. The site reflects an increasing maturity in the bronze casting techniques at that time.
During the Shang and Zhou dynasties, Chinese bronze metallurgy, including mining, smelting and casting, reached a high level of proficiency. Various compositions of copper, tin, and lead made it possible to cast bronze wares with different properties. Ancient Chinese mastered the art of casting molds of different materials and employed a combination of techniques to cast large and heavy bronzes as well as thin and intricate ones. Later, with the introduction of the burn-out and lost-wax techniques, artisans could cast bronzes in one-piece mold. The décor on bronzes became increasingly intricate.
Bronzes glittered with elaborate surface decorations such as polychrome inlays, openwork design, and gilding.
Bronze production technique was the backbone of China's Bronze Age. Without the technique, the rites and music system would not have been implemented in visual or physical existence, nor could the past have been learned from inscriptions. Ancient craftsmen used their amazing intelligence and skilful hands to create and foster the magnificent and splendid Chinese bronze culture.
Advanced mining and smelting of copper are the foundation for bronze casting. Ancient copper mining and smelting sites from the Shang and Zhou dynasties have been discovered in regions such as the middle and lower reaches of the Yangtze River, the middle and lower reaches of the Yellow River, and the west Liao River basin.
These findings demonstrate that our ancestors were capable of efficiently handling complex technical challenges in the processes of prospecting mines, mining, and smelting ores.
Sufficiently high temperature is absolutely crucial to smelting copper ore into copper ingots. The temperature is closely related to the structure of the furnace and the adequate flow of air in the furnace. The vertical furnace discovered at the ancient copper mining and smelting site at the Tonglü Mountain in Daye, Hubei province, is dated as far back as the Spring and Autumn period. It has a quite sophisticated structure. Its use of manpower for air-blowing helped raise the smelting temperature to produce the copper ingots with high purity.
During the Shang and Zhou dynasties, bronzes were primarily cast with clay molds. The molds were made by mixing clay with various materials. After a certain process, the molds acquired superior castability. Shang and Zhou craftsmen mastered the techniques of making clay molds and copper smelting. They also obtained sufficient knowledge of the alloy properties of bronze and knew of making bronzes by selecting and combining proper techniques, such as one-piece casting, separate casting and cast-on, and welding. For objects in high demand, such as tools, chariots, and daily utensils, craftsmen would use the stack casting technique and metal molds to improve production efficiency.
In the burn-out casting, the model is made from combustible materials. A clay mixture is applied to the model exterior to make the mold. The mold and model are then baked under high temperature. In this process, the mold will get hardened while the model is burned away, leaving a cavity where the bronze melt is poured into. The final product will be identical with the model which has been burned. In the mid-Shang dynasty, craftsmen used this technique to make handles for some bronzes.
In lost-wax casting, the wax model fashioned in the shape of the desired object will be coated with a clay mixture.
During firing, the wax melts away, leaving behind a solid clay mold. This technique allows for producing more easily complex three-dimensional and delicate openwork designs, signifying a giant leap in bronze casting technology. The earliest surviving bronzes made through this method date back to the Eastern Zhou dynasty.
Ancient Chinese bronzes are primarily composed of three metal elements: copper, tin, and lead. Different proportions of the three metals produce bronze alloys with different properties. Ancient craftsmen gained and applied the knowledge. The book Kaogong Ji (Artificers' Record) compiled in the Eastern Zhou dynasty records the compositions and smelting temperature of bronze alloy. It is the earliest known literature on smelting of alloys in the world.
Metal composite technology produces metal objects with different alloys through the twice-casting technique, to make full use of the properties of different metals. In the Spring and Autumn period, the Iron smelting technique improved the casting of bronze and iron together in one single piece.
The original colour of bronzes can be either golden or polychrome. Bronzes can be decorated by adopting various techniques including turquoise inlaying, red copper inlaying, gold and silver inlaying, gilding, painting, gold and silver plating, and mother-of-pearl inlay. The colour of bronze itself can change from red to yellow and then to a whiter shade with an increasing proportion of tin. During the Eastern Zhou, craftsmen used this knowledge to create intricate lozenge-shaped or bright spot-patterned decorations. The surface treatment not only makes the bronzes more splendid but also enhances their performance. The invention of “mirror polishing medicines” in no later than the Western Han dynasty, for example, largely helped to brighten, whiten and protect the surfaces of bronze mirrors from erosion.
