Six Hundred Years of Silk and Colour

By Roderick Conway Morris

COMO, Italy 19 June 1999

Fondazione Antonio Ratti, Como
Sample sheet with 12 colours for silks, Chavent Père e Fils, Lyon 1896

In the long history of dyeing, the quantity of silk treated by dyers has always been negligible compared with that of lowlier materials like wool and cotton. But it was in the struggle to find new dyes for silk, the most luxurious of all fibers, that progress was made in extending the handful of colors for fabrics that existed in the Middle Ages to the many thousands available today.

The intimate relationship between silk and the development of dyeing was well recognized several hundred years ago. As a Venetian observed in 1457: 'The fact that silk weaving is one of the most renowned arts of our city is due to our skills in dyeing.' The relentless search for new ways of tinting the silk worm's thread, and the social and symbolic significance that became attached to different colors, is now the subject of an illuminating exhibition, 'Six Hundred Years of Silk and Color,' the latest in a series on aspects of textiles curated by Chiara Buss, who is also the editor of the sumptuous and informative catalogue. The exhibition continues at the Antonio Ratti Foundation on Como's waterfront until July 11.

Six centuries ago, when the show's narrative begins, the range of colors available to the dyer was extraordinarily limited in comparison with that at the disposal of painters. This was because artists could mix colors with water, tempera and, soon after, oil, and they became fixed on plaster, wood or canvas when they dried. The dyer, on the other hand, had continually to contend with the fact that many dyes were not soluble in water, attacked the fibers they were applied to and had to be used with potentially corrosive mordants, or fixatives.

Cost was also a factor, as dyeing required large quantities of often exotic and expensive ingredients, while in the artist's studio a little could go a long way.

The most prized color was red, whose kingly associations went back to the imperial 'purple' of ancient times, and for which the primary source was the dried bodies of the coccus ilicis, a parasite that lived on oak trees in the Mediterranean, Middle East and South Asia.

Bringing new sources of color at far lower cost, the discovery of America represented the first great revolution in the dyeing trade, the second being the invention of chemical dyes in the mid-19th century. For the New World turned out to have plants and insects remarkably similar to those found in the Middle East and Asia on which dyers had come to depend. The cochineal insect, which lived on cactuses, was an excellent substitute for its oak-inhabiting cousins, and the various shades of red it yielded were, if anything, more brilliant and long-lasting.

Cochineal was almost instantly taken up in France and Flanders, but resisted in Italy, whose trade with the Orient was threatened by Atlantic maritime expansion in a host of ways. In Venice, for example, punitive measures against weavers who used it included destruction of their silks and corporal chastisement.

More easily available, and therefore not necessarily regarded as a status symbol, blue was much less a subject of contention. The principal source, woad, with which Celtic warriors painted their bodies, was obtained from a native herbaceous plant and had been widely used in Europe since time immemorial.

Later, dyers turned to Indian indigo, derived from a very similar plant, though erroneously believed in Europe to come from a mineral, and declared by some Western protectionists to be manufactured by the devil. Once again, the conquest of America had an impact, with the import of American indigo and of an alternative dye, extracted from logwood or campeachy wood, common in Central America and the Caribbean.

Yellow was obtained from an indigenous European plant, weld, the range of shades in due course extended by saffron and other tints from the East. Surprisingly, considering green's superabundance in nature, in the West at least no vegetable or animal source was identified for green dyes, so greens had to be made by successively immersing fabrics in vats of yellow and blue.

The two seemingly plainest of colors, black and white, proved the most fiendishly difficult to reproduce. Since silk is naturally yellow, for white the challenge was to get the color out, not put it in. This was originally done by smoking the material with burning sulfur in a confined space and then exposing it to sunlight, a process that drastically shortened the life of the fabric, not to mention that of the unfortunates charged with carrying it out. In the late 18th century, chlorine was substituted for sulfur, but this was scarcely less hazardous to human health.

The final breakthrough came in 1799 with 'bleaching powder,' which was infinitely cheaper and safer. This innovation facilitated the universal fashion for white wedding dresses, which would have been inconceivable as long as white silk remained so costly and delicate.

Pure black was equally elusive and dyers went to fantastic lengths to solve the problem. A 15th-century Genoese formula consists of gall, gum, vitriol, iron filings, madder, vinegar and soap. Damage suffered by fibers remained an eternal headache, but the Venetians and above all the Genoese did succeed in producing reasonably durable black silks and velvets, and dominated the market for them until the appearance of chemical alternatives in the 19th century.

The invention of chemical dyes, also well illustrated in the show, is a whole fascinating chapter in itself. Their advent produced an explosion of color, shades and patterns, transforming clothes and furnishings, and bringing color into the lives even of the least prosperous.

The pièce de résistance in this section is the dazzling array of the thousands of minutely graded and matched sample colors of the 'Cartes de Nuances' produced twice yearly by the Chambre Syndicale of the Lyon dyers between 1906 and 1939. These are an amazing monument to chemistry, industry and ingenuity, and a fitting finale to an exhibition that demonstrates that an appreciation of the history of color is far too interesting and important to be left to the specialists alone.

First published: International Herald Tribune