Madder – Rubia tinctorium, Rubia cordifolia, and Morinda citrifolia. Madder is one of the oldest dyestuffs known. It is most frequently used to produce turkey reds, mulberry, orange-red, terracotta, and in combination with other dyes and dyeing procedures can yield crimson, purple, rust, browns, and near black. The primary dye component is alizarin, which is found in the roots of several plants and trees. Madder is cultivated and grows wild throughout India, south east Asia, Turkey, Europe, south China, parts of Africa, Australia and Japan. Madder is a complex dyestuff containing over 20 individual chemical substances. Alizarin is the most important of these because it gives the famous warm Turkey red colour. Also present in this wonderful plant is munjistin, purpurin, and a multitude of yellows and browns. Madder is dyed at 35-100% WOF for a medium depth of shade.
Mordanting: use alum mordant at 15% WOF for protein fibres. For cellulose mordant with tannin at 8% WOF and then alum at 15%, or alum acetate at 8%. For dark brick reds use alum acetate (instead of the normal mordanting alum which is potassium aluminum sulfate).
Dyeing: Madder develops to its deepest and richest reds in hard water – water containing calcium and magnesium salts is ideal. If the water is soft add calcium carbonate (a single Tum’s tablet to 4 litres of water works well). Add dye material to dye pot and cover with water. Bring up to about 60ºC (140ºF) and hold for an hour. Add fibres and continue cooking for another 1-2 hours. For clear reds of rubia tinctorium do not let the temperature go above 72ºC (160ºF). At higher temperatures the browns of this madder plant come out and dull the colour. Rubia cordifolia is not as affected by high temperature. The madder dyebath can be reused two or three times for lighter shades.
Because of the different dye components present in the madder plant, the dyer can coax many colours out and onto the cloth by manipulating the mordanting process, the pH, the temperature, and the dye process. There are hundreds of madder recipes used historically that are intriguing to try including one from Turkey which brings out the purpurin from madder and gives a purple.
Madder, in combination with cochineal yields a true red, with iron yields garnet, bright orange with alum and cream of tartar, brick red with alum mordant and a higher heat, the addition of acetic acid or vinegar plus iron will push the colour to a rich brownish-purple.
Lac Extract – a red dye extract from the scale insect Laccifer lacca which is found throughout India, south east Asia, Nepal, Burma, Bhutan and south China. It is found both in the wild and cultivated. The female lac insects invade host trees (mainly fig and acacia) and the insect secretes a resin that contains the red dye. When harvested, the resin is taken off the branches and is known as stick lac. The resin is also used to make shellac. The dye must be extracted from the resin before it can be used to colour cloth.
Lac extract yields crimsons to burgundy reds to deep purples. The colourant is similar to cochineal but colours achieved are warmer, softer, and more muted. The lac dye has high light and washfastness on silk and wool. 5-8% dye to WOF is all that is needed for a medium depth of shade.
Mordanting: use alum mordant at 15% WOF for protein fibres. For cellulose mordant with tannin at 8% WOF and then alum at 15%, or alum acetate at 8% – but note that lac extract has reduced light and washfastness on cellulose fibres.
Dyeing: Use at 10-15% WOF. Dissolve extract in water and simmer with fibre for 45 minutes, leaving overnight for richest colours. This dye is very sensitive to change in pH and develops to its fullest colour potential with the addition of cream of tartar at 6% WOF. The addition of an alkali like soda ash will yield plum purples and the addition of iron will give blackened purples.
Indigo (natural) – natural indigo powder is an extract prepared from Indigofera tinctoria which is cultivated for this purpose. Indigo is the legendary source of colourfast blues and its ability to produce a wide range of shades has made it the most successful dye plant ever known. Indigo grows all over the world but flourishes best in hot, sunny, humid areas. Indigo can give clear blues that range from the tint of a pale sky to a deep navy that is almost black. Our indigo comes from a farm in south India and is very strong (approx 50% indigotin). It reduces beautifully in an indigo vat.