Although glass was probably made in China from as early as c. 300 BC, most Chinese glass dates from after c.1662, when a glasswork was established in the Forbidden City. Glass was hardly known in China until European Jesuits introduced its manufacture into the palace.
Chinese glass was largely used to imitate more precious materials such as white jade, lapis lazuli and other valuable minerals. One surprisingly common item is snuff bottles that was made in huge numbers as Imperial gifts.
However, it is clear that glass, which had hardly been used in China before the Qianlong era, was particularly popular. The Qianlong emperor appointed two Jesuits to run the imperial glass workshop in the Yuanming yuan and they were soon sending home to Europe for chemicals to colour glass in new ways and and supervising the enamelling of Western scenes on the tiny bottles.
In 1983 Yang Boda’s study of glass wares from the Qing Dynasty (1644-1911) was published. Working with records of the Workshops of the Imperial Palace (Zaobanchu), Yang was able to chart the course of Imperial glassmaking from the Yongzheng reign (1723-35) to the end of the Xuantong (1909-11) period. However, since records for the Kangxi era (1662-1722) were lacking, little was known about the Imperial glass workshop the emperor had established in 1696.
Fortunately, historical documents in the archives in Rome and the Vatican contained more specific information regarding the founding of the glassworks. They revealed that the workshop itself, was located within the confines of the Imperial City on a piece of land adjacent to the French Jesuits’ church. This proved to be in accordance with two eighteenth century Chinese texts which state that the entire complex was located on the east side of a street named Canchikou.
From several letters dating to 1696 and written by Jean de Fontaney, conserved in the Japonica/Sinica division of the Archivum Romanum Societatis Iesu, we learn that this glasswork had been erected by Kilian Stumpf and that it was already producing glass wares.
According to the accounts written by Matteo Ripa and housed in the archives of Archivio Storico de Propaganda Fide, in 1711 the glass workshop was still under Stumpf’s direction, and in May 1715 Ripa recorded how Stumpf had built many furnaces for glass making, while attending to the needs of a great number of craftsmen, all of which required his constant attention.
Continuing on, Theodorico Pedrini, sent a request to Rome for examples of glass with gold sparkles that shine. Pedrini also added that the glassworks was experiencing difficulties in making this variety. The glass batch for this was in fact hard to make and nearly impossible to work by blowing. Nonetheless, in 1705 Kangxi presented the military governor of Jiangsu with seventeen pieces of glass among which were two blue vases speckled with gold.
His description brings to mind the copper particles found in aventurine glass. Examples of transparent blue glass items that contains spangles (pasta stellaria) imitating aventurine, may be found in the collection of the Beijing Palace Museum however I find it more likely that the reference is rather towards imitations of Lapis Lazuli, a stone very close to the Jesuit's heart not the least through its reference towards the imposing and luxurious St. Ignatius Chapel in Chiesa del Gesù, in Rome, the home church of the Jesuits and housing the very remains of its founder Ignatius Loyola, his chapel heavily inset with this particular stone.
A letter written by Jean-François Foucquet, and preserved in the Biblioteca Apostolica Vaticana describes in detail the gifts Kangxi was sending to the King of Portugal in 1721. Among the glassware we find descriptions for plates the color of celestial red; cups with flower pattern the color of blue sky after rain (yuguo tianqing), pots and plates in the same shade, plates of sky-blue (tianlan), cups and plates of white glass ornamented with flowers, and five cups of white glass and adorned with gilt on the exterior.
Foucquet's references to glass with flower patterns recalls a mention by Lodovico Antonio Appiani, of having been in a room 'full of young artisans who were carving floral patterns on the glass wares,' while the distinctions made on Foucquet’s list between vessels of 'sky-blue' and the 'blue sky after rain' colours impart a distinctive Chinese sensibility. As to the color of 'blue sky after rain,' this description was probably derived from that of the mysterious Chai stoneware made during the reign of Emperor Shizong (953-959) of the Five Dynasties. These highly subjective names also includes such names as 'clair de lune' and 'celestial red'.
The Qing dynasty Yongzheng emperor (1723-35) is said to have exhibited a pronounced preference for vessels made of bright red and purple glass. The method utilized to achieve these colors is believed to have been transmitted to China by Kilian Stumpf who had attended the Jesuit college in Mainz where the latest modes to produce ruby glass were known. This process included the addition of colloidal gold (gold dispersed as fine particles) to the glass formula. That this technology had been introduced to China has been confirmed by analytical studies of specimens from the Kangxi and Yongzheng periods, which showed that the red, pink, and purple enamel colors employed in decorating porcelain had been prepared from ruby glass which contained colloidal particles of gold.
A commonly held view postulates that the overall quality of Imperial glassmaking began to decline in the last quarter of the eighteenth century and that thereafter, nothing of any noteworthy significance was produced. This as so many assumptions of the later Qing dynasty could be challenged however, it is likely that the number of objects could be less then from the earlier periods.
In essence, João Mourão, maintains that the Reverend Father Kilian Stumpf was instrumental in his teaching of the two arts of making glass and enamel colors in the Imperial palace works. Moreover he taught the construction of making ovens and small kilns, a knowledge that the Chinese 'today in their ingenious manner use to fashion very curious objects,' (fazem Hoje obras muito curiozas).