Dyestuffs

Information summarised from Nigel Heard: Wool: East Anglia’s Golden Fleece

Dyeing was a difficult and expensive process requiring knowledge of scientific processes and reactions. Some dyestuffs such as woad (blue), and saffron (yellow) could were grown in East Anglia. Woad was a noxious product requiring substantial processing before it could be used. It was grown in the Fens. Subtle shades of green and yellow came from nettles, lichens, onions and oak bark. A variety of berries produced soft blues and purples. Red could be made from sorrel and ladies bedstraw; black from alder bark and yellow iris. All these dyestuffs had to be chopped and boiled before use; great quantities were required and great care had to be exercised over recipes and treatments or the result would be uneven.

The more exotic dyestuffs and most mordants were imported, master dyers needed to be men of substance to arrange the capital outlay, as dyestuffs were expensive. Fabric dyed with brighter blues, reds and yellows fetched high prices. Red dyes such as Madder came from the Mediterranean and the Mediterranean insect ‘coccus ilicis’ gave ‘grayne’, a brilliant scarlet. Weld also known as dyer’s plant, grown in France and Germany, produced a bright yellow. Iindigo were both imported for its superior blue.

Most natural dyes needed mordants made from metallic oxides to set the colour. Most cloths were mordanted before dyeing. Alum was widely used, with the addition of a small amount of cream of tartar to brighten the colour. Tin chloride, iron sulphate and bichromate of tin were also imported as mordants. The precise receipes of dye-stuffs and mordants needed to obtain particular colours were closely-guarded secrets kept by the individual dyeing families. Norwich dyers buillt up great expertise which they used to great effect in the characteristic bright warp-coloured patterns and in the famed 'Norwich Red' shawls.