Classical Studies 2700B

TEXTILES: weaving and dyeing

Weaving: types of loom and their characteristics in early cultures. Basic loom in classical antiquity was warp-weighted vertical loom (that is, the warp threads [N.-S.] have loom weights to which they are tied in bundles); this was the only type used in Greece until end of 5^th century BC, and maybe later: see item C just below middle of hand-out page 1. Description of its various parts (using a better diagram—on a slide). Note terminology: warp and weft; heddle-rod and its bracket; shed-rod; “natural” shed and “artificial” shed. How this loom worked. Replaced in Roman Empire by free-standing two-beam loom (item B on page 1 of hand-out): its differences from earlier loom. In late antiquity reversion to horizontal looms with multiple heddle rods for elaborate weaves.

Dyeing: problems with ancient dyed materials; also dyes in ancient world were somewhat impure; so considerable “colour uncertainty”—consequences of this. For example, little distinction between violet, scarlet and purple: all much the same and probably would appear rather dingy to us (true until discovery of aniline dyes in 19^th century [1856 by William Perkins]). Range of colours, too, probably quite limited. Also, formulas for dyes were closely-guarded trade secrets in families.

Various types of dyes:

Red: goodish range, both from animal and vegetable sources. Most important were kermes and cochineal, both derived from female insects of genus Coccidae; description of Kermes from Kermococcus vermilio. This produced a water-alcohol soluble dye, which required a mordant to fix it to cloth (alum and urine in this case). Used on wool, leather and silk. (In Middle Ages this dye was known as “Venetian scarlet”.) Also, another important, but much cheaper red dye was madder (also called “the root”); from pulverized root of a plant c. 3 feet high (required iron alums as mordants); widely cultivated everywhere until synthesised in 1868. Other common red dyes were henna, dragon’s blood (called “cinnabaris” by Pliny), and perhaps Brazil wood (in Latin “brasilium”).

Blue: not too many; most important was woad (always associated with ancient Britain); made from leaves of an herbaceous plant native to E. Europe (really a mild form of indigo). Indigo was from a plant native to India; contained 30x as much blue material as woad; always rather expensive in ancient Mediterranean; classical sources unsure whether it was a vegetable pigment or a mineral.

Purple: most esteemed of all dyes in ancient world; extracted from certain molluscs on Easternmost coast of the Mediterranean, between Tyre and Haifa > “Tyrian purple”; also called “murex” from mollusc Murex brandaris. Dye industry there goes back to at least 1500 BC and lasted until Arab conquest in AD 638 (=AH 16). The colouring material is a secretion contained in a small cyst in the mollusc (12,000 molluscs needed to produce 1.4 gm of the stuff; hence huge cost). This is a photochemical dye: cloth dipped in the solution turns yellow and, when exposed to strong sunlight, by further oxidization becomes purple. Purple was very much a class matter in antiquity; in Rome could be worn only by certain social ranks.

Other dyes: yellow (safflower, saffron and broom), a few greens (not v. common) and blacks and browns.

Actual dyeing process: large boilers containing copper vats. Two main types of dyes: mordant dyes (e.g., kermes, madder, woad, saffron, brazil wood), where dye plus mordant form a lake, which adheres to fabric and produces fast colours; and vat dyes, where dyestuff is usually insoluble and has to be reduced to a colourless solution in which material is dunked and then exposed to air (or boiled) for oxidization to take place (e.g., Tyrian purple and indigo).

Finishing (or fulling); important material is “fuller’s earth” (a kind of clay—actually, finely divided hydrated aluminum silicate), which absorbs grease and removes dirt and “plumps up” the cloth. The fuller has two jobs—to “finish” cloth as it comes from the loom and to launder soiled garments. The processes.