Pouring bowl (14th century)

Blue: Alchemy of a Colour explores Asian and European works of art from the seventh century to the present inspired by the colour blue. Comprising more than seventy ceramics, paintings, prints and textiles, the exhibition focuses on cobalt blue and indigo: two of the most distinctive and influential colourants employed worldwide. The desirable blue-and-white palette has inspired artists throughout Asia and Europe to create works in a range of media, styles and techniques, and instigated trade and cultural connections between the two worlds. Blue has symbolic significance in many cultures and features in prestigious ceremonial textiles and garments which convey the status of the wearer and the importance of certain occasions, yet everyday clothes of the working class throughout Asia and Europe were also coloured blue. Although synthetic blue pigments and dyes developed in the eighteenth and nineteenth centuries and have since been widely adopted, the use of naturally sourced blue colourants continues due to their unique characteristics, useful properties and symbolic resonance.

The symbolism of blue

Across Asia and Europe the colour blue has acquired various symbolic associations. Blue is linked with specific deities in Hinduism and Buddhism, particularly the Hindu god Vishnu who is coloured blue, as are his avatars or incarnations, and allies are all coloured blue. In China the word qing is used to denote green, blue and black, and shades in between. As one of the five basic colours used to visualise world order (red, white, blue/green, yellow and black), blue is associated with a compass direction (east), a season (spring), an element (wood) and a constellation (green dragon), and the colour generally signifies the natural world, springtime, youth and immortality.

Techniques of indigo dyeing

Indigo blue is used as a dye for textiles and a pigment for paintings and prints. It is sourced from a range of plants, the best known being Indigofera tinctoria (‘true’ indigo), which has been used to dye textiles in India since 2000 BCE. Plants that contain indigotin, the active ingredient in indigo dye, are widely available, and indigo’s resistance to light and washing, as well as its ability to provide numerous shades of blue from one dye bath, has resulted in it becoming a worldwide phenomenon.

Until the seventeenth century the woad plant (Isatis tinctoria) was the primary source of indigo blue in Europe; however, Indigofera tinctoria contains a higher concentration of the dye and consequently replaced woad as the preferred blue dyestuff. Natural indigo was in turn replaced by synthetic indigo, developed in Germany in 1878, although the natural indigo continues to be cultivated for its unique qualities. Techniques employed to pattern indigo-dyed cloth are explored in textiles from Egypt, Japan, China, Central Asia, India, Indonesia and Italy. Patterning with printed, painted and tied resists, which produce a white pattern on an indigo blue field, are contrasted with positive blue patterns produced by printing or weaving.

Indigo was also used as a pigment in Japanese woodblock prints (ukiyo-e) but was supplanted by synthetic pigments, notably Prussian blue which originated in Germany in 1709 and was widely used in Japanese prints from the 1820s onwards.

Blue garments for everyday wear and as markers of status and prestige

The ubiquity of indigo dye, and its special properties, has resulted in blue becoming the colour of everyday clothes of the working class in Europe and Asia. In many cultures indigo is thought to possess protective and preservative properties, acting as a natural insecticide due to the chemical rotenoids it contains and having the ability to prevent disease or heal wounds if worn next to the skin.

Predominantly blue garments are also some of the most prestigious textiles, bestowing status on their wearers and worn on important ritual occasions. The quality of their dyeing and weaving determines their social value. Added prestige may be signified by the incorporation of valuable materials, such as gold and beads, extra colours, patterns and techniques or special finishes, including calendaring, into the blue garments. Deceptively simple blue cloths often play an integral part in important rituals marking the path through life of an individual or a community.

Cobalt blue-and-white ceramics

Cobalt is a silver-white metallic element which occurs naturally as a compound with various other minerals and gives a distinctive deep blue colour to glass, ceramics, inks and paints. The first evidence for Chinese use of cobalt to produce blue decorated ceramics is found during the Tang dynasty (618–906); however, the succeeding Song dynasty showed little interest in cobalt blue. It was during the Yuan dynasty (1279–1368) that white porcelain decorated with underglaze cobalt blue began to be produced in great quantities.

The Persians, whose own ceramic tradition employed cobalt blue, greatly admired lustrous white Chinese porcelain but were unable to produce this high-fired ceramic body themselves. Evidence suggests that Persians began commissioning and importing blue-and-white porcelain from the Chinese kilns in the fourteenth century. It is also likely that the cobalt used in Yuan blue-and-white wares, referred to as ‘Islamic blue’, was imported from Iran. That the birth of Chinese blue-and-white porcelain was the result of complex cross-cultural interactions is further suggested by the fact that many of the motifs employed on Yuan blue-and-white wares appear related to Uighur and Mongol textile designs.

Although it may have begun as a ware destined for export to Persia, Chinese interest in blue-and-white porcelain quickly developed. By the advent of the Ming dynasty (1368–1644) it was being produced in enormous quantities at the kilns of Jingdezhen. Imports of cobalt from Persia could not match the growing demand for the mineral, and Chinese cobalt sources began to be exploited with ever greater intensity. It was this Ming blue-and-white that began to reach Europe in small quantities, igniting a European passion for these marvellous ceramics and a quest to discover the secret of their production.

The chemistry behind the production of true porcelain eluded European ceramicists until the successful formulation of a hard-paste porcelain in Saxony in 1709. Prior to this discovery, European potters emulated Chinese porcelain in low-fired earthenware decorated with white glazes and cobalt blue. Opaque tin-glazed earthenwares decorated with underglaze cobalt blue and lustre glazes were introduced into Spain by Muslim potters in the tenth century. Much admired in Italy, where they were imported in quantity, these Spanish ceramics stimulated the production in the fifteenth century of Italian tin-glazed earthenwares decorated with cobalt blue imported from Northern Africa or the Eastern Mediterranean. In the fifteenth century the desire to emulate Chinese blue-and-white porcelain also saw a ceramic industry flower in Iznik in Anatolia, where fine earthenwares decorated with cobalt blue were produced for the Ottoman court.

The establishment of seaborne trade routes to Asia in the sixteenth century saw Chinese blue-and-white porcelain begin to arrive in Europe in ever greater quantities. This triggered a ‘chinamania’ resulting in ever greater demand for imitations of the still costly Chinese originals. Perhaps the highpoint of European earthenware imitations of blue-and-white porcelain was reached in the town of Delft in the Dutch Republic in the second half of the seventeenth century. Delft potters perfected an opaque tin glaze of pristine whiteness which, when decorated with cobalt blue imported from the Erzgebirge mountains in Saxony, imitated the lustrous appearance of porcelain so closely that it gained the name ‘Delft porcelain’.

With the discovery of the method for making true porcelain in the eighteenth century, European potters were at last able to make porcelain equal in translucence to Chinese blue-and-white originals. Mineral-rich Saxony exported calcined cobalt pigment throughout Europe, allowing local porcelain industries to produce their own versions of Chinese porcelains that copied not only their colour palette but also their decorative motifs, although these often morphed into bizarre and exotic forms.

Blue: Alchemy of Colour brings together indigo textiles and cobalt-decorated ceramics to explore the themes of trade, artistic exchange, the status and symbolism of the colour blue and its ubiquity across the globe.