The type and qualities of a fiber determine various aspects of a textile's production, from the technological processes of weaving techniques to patterns and dyes. Animal Fibers—the second installment by the Department of Textile Conservation in a series detailing the characteristics of plant, animal, and synthetic fibers—focuses on wool, hair, wild and cultivated silk, and feathers.
On view is a selection of artifacts from around the world that illuminate the department's examinations of materials and weave structures, using innovative analytical equipment, to enhance our understanding of the Museum's collection of textiles.
Wool from sheep, goats, and camelids has been the most commonly used material across all types of textiles, from clothing to rugs, throughout history. The quality of fiber may depend on the animal's breed, as well as on which part of the body the fiber is found, and determines the process for transforming the wool into a finished product.
Each animal has diverse types of fibers, which are separated and used for specific purposes. Sheep have coarser and longer wool on their backs, used preferably for warp, and softer, shorter fibers on their necks and bellies, used primarily for weft. Goats and camelids have fibers of varied quality distributed throughout inner and outer layers. One of the coarsest wool fibers is from the backs of Turcana sheep from the Carpathian Mountains in central and eastern Europe. Finest among animal fibers is Shahtoosh, the wool of Tibetan antelopes, or chiru, inhabiting the Himalayan wilderness.
For weaving, the relatively short fibers first require spinning to create long threads. Alternatively, wool fibers can be felted, a process possible due to the fiber's surface structure of overlapping scales, which create a jagged edge as they point away from the filament. Coarse wool fibers that are straight rather than crimped require weaving before felting because the scales are positioned closer to the fiber's body, preventing them from latching onto one another.
Silk, the most valued fiber since the Neolithic era, originated in China, which for centuries maintained a monopoly on its production by raising silkworms, a process known as sericulture. In 200 B.C., sericulture spread to Korea and, later, in the fifth century, to Japan. The Silk Road led to the expanded development of sericulture, resulting in the production of luxurious silk that was as costly as gold. By the sixth century, sericulture had extended from central Asia to the Byzantine Empire; by the 10th century, to Spain; by the 15th century, to Italy; and in the 17th century, to southern France.
Silk is a natural fiber produced by small caterpillars of several moth species. There are two groups of silk fiber: cultivated mulberry silk (from Bombyx mori) and wild silk, such as Tussah, Eri, and Muga from India, the most popular among more than 500 silkworm species. During a silkworm's final transformation from larva to moth, it extrudes sericin-coated fibroin, spinning it as a protective shell. Before the pupa of a cultivated silkworm can make its way out and damage the cocoon, it is killed inside by heat, steam, or salt. An approximately one-kilometer-long fibrous filament can then be collected from the cocoon and even reeled and slightly twisted to add extra strength for weaving.
Processing wild silk is more challenging since the cocoon is coated with the mineral calcium oxalate and when the pupa breaks through, it damages the fibers, which then must be spun to make a thread.
Specialty fibers, such as those from horses, cows, yaks, and birds, play a significant role in many of the world's cultural artifacts. The use of nontraditional animal fibers in textiles and accoutrements demonstrates different cultures' utilization of indigenous materials as well as their ingenuity and skill. The morphology, or shape and structure, and scale patterns among woolen fibers can appear similar, which can make identifying an animal fiber challenging. However, environmental conditions and the animal's nutrition are important factors in the development of unique fiber characteristics, including the size of the medulla, scale patterns, and length, which provide helpful clues with regard to the attribution and creation of special objects.
The processing of these fibers is not typical—as is spinning or splicing fibers into yarns—with the exception of the peacock feather plied with a silk thread as seen in the Chinese rank badge here. Many specialty fibers are used directly from the animal as a single thread with an alternative type of processing, such as lacquering, adhesion, or braiding, which mimics more common fibers such as wool and provides strength and texture. In producing unique textiles, various cultures use their natural resources to fit their needs both practically and aesthetically. The labor-intensive techniques developed by early artisans make up living traditions that are recognized today as intangible cultural heritage.
Woman's ceremonial robe (detail), Qing dynasty (1644–1911), 19th century. China. Silk, cat fur, 53 in. (134.6 cm). The Metropolitan Museum of Art, New York, Bequest of Duchesse de Richelieu, 1972 (1973.28.6)