THE OZONE FADING OF TRADITIONAL CHINESE PLANT DYES
YUN YE, LYNN G. SALMON, & GLEN R. CASS
2 2. TRADITIONAL CHINESE DYES
Plant dyes were the dominant materials used for textile dyeing in ancient China. Chinese literary sources state that, as early as the Western Zhou Dynasty (1045–711 b.c.), a system of dyeing techniques was developed. The plant dyes used then include (Wu and Tian 1986):
- blue: indigo (Polygonum tinctorium)
- red: madder (Rubia cordifolia)
- purple: gromwell (Lithospermum erythrorhizon)
- yellow: gardenia (Gardenia jasminoides Ellis)
- black: hazel bark (Corylus chinensis)
During the Spring and Autumn Period (722–481 b.c.) and the Warring States Period (480–222 b.c.), mordant dying with plants containing tannic acid was widely used to yield black. The mordant employed was qing fan (iron salt) (Wu and Tian 1986). In addition to madder, safflower, which was introduced to China from the northwest tribes, became an important dyestuff during the Han Dynasty (202 b.c.–a.d. 220). It was taken to Japan in the Tang Dynasty (a.d. 618–960). During the Ming Dynasty (a.d. 1368–1644), numerous plants were employed from which dyes were extracted (Li 1981; Song 1982). In The Exploitation of the Works of Nature (Tian gong kai wu), Song Yingxing (b. 1587) reported four different plants from which indigo can be extracted, all widely planted as dyestuffs in China (Song 1982):
song lan(also known as cha lan): Isatis tinctoria L. var. yezoensis (ohwi) Ohwim
liao lan(also known as xian lan): Polygonum tinctorium
ma lan (distributed in northern China): Indigofera tinctoria L. and Strobilanthes cusis (Nees) O. ktze
wu lan (distributed in southern China, also known as mu lan, huai lan): Indigofera tinctoria L.
These natural indigos were not only used in China but also exported to Europe before synthetic organic dyes were developed (Wu and Tian 1986).
More detailed descriptions of ancient Chinese dyes are not available. However, the ancient cultures of China and Japan influenced each other deeply. Sources and chemical compositions of plant dyes used in ancient Japanese textiles are presented by K�z� Hayashi (1979). Table 1 provides a brief summary of the results reported by Hayashi.
Table 1. SOurces and Chemical Composition of Plnat DYES USed in Ancient Japan
|Color ||Japanese Name ||Latin Name ||Dye COnstituent
|yellow ||kihada ||Phellodendron amurense ||berberine
|yellow ||woren ||Coptis Japonica ||berberine
|yellow ||kariyasu ||miscanthus tinctorius ||anthraxin
|yellow ||ukon ||curcuma domestica ||curcumin
|yellow ||kuchinashi ||Gardenia jasminoides Ellis ||crocin
|yellow ||enju ||Sophora japonica ||rutin
|yellow ||haze or haji ||Rhus succedanea ||fustin
|red ||alkane ||rubia akane ||Pseudopurpurin
|red ||seiyo-akane ||Rubia tinctorum ||alizarin
|red ||benibana ||Carthamus tinctorius ||carthamin and carthamon
|red ||suwo ||Caesalpinia sappan ||brazilein
|violet ||murasaki ||Lithospermum erythrorhizon ||shikonin
|blue ||ai ||Polygonum tinctorium ||indigotin (indigo)
|blue || ||Strobilanthes flaccidifolium ||indigotin (indigo)
|brown || || ||tannins
In preparation for the present experiments, samples of silk cloth dyed by traditional methods were prepared by the staff of the Suzhou Silk Museum in Suzhou, China. Staff members extracted the dyes directly from the original plant materials, and examples of both the dyed silks and the unextracted plant materials were provided for use in our experiments. The colorants furnished were identified by their Chinese names by the Suzhou Silk Museum and have been described further here based on an extensive literature review. The colorants examined are listed in table 2, and some details of their origin and properties follow.
Table 2. The Traditional Plant Colorants Tested in this Experiment
Su mu: sappan wood (Caesalpinia sappan). The sappan tree is a small evergreen tree, native to India and the Malay Peninsula, also called Brazil wood. The heartwood or the bark yields a red dye when mordanted with alum (Wee 1992). The dye constituent is brazilin (C16H14O5), the leuco-compound of brazilein (C16H12O5), which is deep red to brown in color (Pratt 1947). The mordanted dye displays good fastness toward washing (Society of Dyers and Colourists 1971).
Jiang xiang: dalbergia wood (Lignum dalbergiae odoriferae). The colorant, derived from the wood of a tropical tree, yields a beige color (Wee 1992).
Hong cha ye: black tea (Thea sinensis). The dye is extracted from the fermented and dried leaves of a small evergreen shrub. The main components are caffeine and tannin (10–20% gallotannic acid) (Grieve 1971).
Wu bei zi: Chinese gall (Rhus chinensis). The excrescence produced by parasitic aphids on the leaves of Rhus chinensis mill, or Rhus potanimii maxim, is gathered and extracted (Liu 1988). The main constituent is gallotannin. The total tannin content is up to 70%, the richest known concentration in the plant kingdom (De Wit 1965).
Zi cao: gromwell (Lithospermum erythrorhizon). The original plant source is an herb from northern China and Japan, the roots of which give a purple dye (Wee 1992). It is one of the most important mordant dyes used in ancient China. The dye constituent is shikonin, a derivative of naphthoquinone (Hayashi 1979).
Ban lan gen: indigo (root) (Isatis indigotica Fort. or Isatis tinctoria L.) (Ehling and Swart 1996). The colorant is derived from the dry root of what are commonly known as indigo plants. The leaves of indigo plants contain the colorless glycoside indican (Society of Dyers and Colourists 1971), the precursor of the blue dye indigo, which has been widely studied elsewhere. The root of these plants, which is the source of the dye produced by the Suzhou Silk Museum staff, yields a yellow dye. The colorant is possibly indigo yellow (Tang 1991).
Huang zhi zi: gardenia (Gardenia jasminoides Ellis). This was one of the most widely used dyes in middle China in ancient times (Needham 1954; Forbes 1987). In Records of the Historian, Sima Qian (2d century b.c.), depicts “thousands of mu [15 mu is about 1 hectare] of dyeing gardenia,” which suggests that it was a very popular dye during the Qin (221 b.c.–207 b.c.) and Han (202 b.c.–a.d. 220) Dynasties. The husks of seeds of the gardenia yield a bright yellow. The dye constituent is crocin (Hayashi 1979).
Ju zi pi: tangerine peel (Citrus tangerina Hort). The Suzhou Silk Museum provided a dyed silk sample but did not provide dried plant material for ju zi pi. The yellow colorant applied by us to create the paper sample was extracted from the peel of tangerines purchased from a Chinese supermarket.
Huang bai: Chinese yellow cork tree (Phellodendron amurense Rupr. or Phellodenron chinense Schneld). The deeply fissured corky bark of this deciduous tree can be extracted to yield an intense yellow. The dye constituent is berberine (Hayashi 1979).
Zi ding cao: violet (Viola philippica). The extract from this herbaceous plant (Liu 1988) yields a yellowish brown color when applied on silk.
Jiang huang: turmeric (Curcuma longa L.). This is a perennial plant with a stout underground stem (Wee 1992). The dye constituent is curcumin (C21H20O6), a bright yellow coloring substance that dissolves readily in water (Pratt 1947). It was an important dye in Asia as well as in Europe prior to the discovery of aniline dyes.
Da qing ye: indigo (leaf) (Isatis tinctoria L.). This dye is similar to ban lan gen but is made from the unprocessed leaf of the indigo plant rather than the ground root.