Vegetable Dyes.
by Ethel M. Mairet.
CHAPTER I
WOOL SILK COTTON AND LINEN
WOOLS are of various kinds:--
_Highland, Welsh and Irish_ wools are from small sheep, not far removed from the wild state, with irregular short stapled fleeces.
_Forest or Mountain sheep_ (Herdwick, Exmoor, Cheviot, Blackfaced, Limestone) have better wool, especially the Cheviot, which is very thick and good for milling.
_Ancient Upland_, such as South Down, are smaller sheep than the last named, but the wool is softer and finer.
_Long Woolled sheep_, (Lincolns, Leicester) with long staple wool (record length, 36".) and fleeces weighing up to 12 lbs. The Leicester fleece is softer, finer and better than Lincoln.
To the end of the 18th century _Spanish wool_ was the finest and best wool in the world. Spanish sheep have since been introduced into various countries, such as Saxony, Australia, Cape Colony, New Zealand; and some of the best wools now come from the Colonies.
_Alpaca, Vicuna and Llama_ wools are from different species of American goats.
_Mohair_ from the Angora goat of Asia Minor.
_Kashmir Wool_ from the Thibetan goat.
_Camel_ hair, the soft under wool of the camel, which is shed annually.
The colour of wool varies from white to a very dark brown black, with all shades of fawn, grey and brown in between. The natural colours are not absolutely fast to light but tend to bleach slightly with the sun.
The princ.i.p.al fleeces are:
_Lambs_, 3 to 6 months growth, the finest, softest and most elastic wool.
_Hogs and Tegs_: the first shearing of sheep that have not been shorn as lambs.
_Wethers_: all clips succeeding the first shearing.
Wool comes into the market in the following condition. 1. _In the grease_, not having been washed and containing all the impurities. 2.
_Washed_, with some of the grease removed and fairly clean. 3.
_Scoured_, thoroughly cleaned and all grease removed.
Wool can be dyed either in the fleece, in the yarn, or in the woven cloth. Raw wool always contains a certain amount of natural grease.
This should not be washed out until it is ready for dyeing, as the grease keeps the moth out to a considerable extent. Hand spun wool is generally spun in the oil to facilitate spinning. All grease and oil must be scoured out before dyeing is begun, and this must be done very thoroughly or the wool will not take the colour.
WATER
A constant supply of clean soft water is an absolute necessity for the dyer. Rain water should be collected as much as possible, as this is the best water to use. The dye house should be by a river or stream, so that the dyer can wash with a continuous supply. Spring and well water is, as a rule, hard, and should be avoided. In washing, as well as in dyeing, hard water is injurious for wool. It ruins the brilliancy of the colour, and prevents the dyeing of some colours.
Temporary hardness can be overcome by boiling the water (20 to 30 minutes) before using. An old method of purifying water, which is still used by some silk and wool scourers, is to boil the water with a little soap, skimming off the surface as it boils. In many cases it is sufficient to add a little acetic acid to the water.
TO WASH WOOL
In a bath containing 10 gallons of warm water add 4 fluid ounces of ammonia fort, .880, 1 lb. soda, and 2 oz. soft soap, (potash soap).
Stir well until all is dissolved. Dip the wool in and leave for 2 minutes, then squeeze gently and wash in warm water until quite clear.
_Or_ to 10 gallons of water add 6 oz. ammonia and 3 oz. soft soap. The water should never be above 140F. and all the washing water should be of about the same temperature.
Fleece may be washed in the same way, but great care should be taken not to felt the wool--the less squeezing the better.
There are four princ.i.p.al methods of dyeing wool.
1st.--The wool is boiled first with the mordant and then in a fresh bath with the dye.
2nd.--The wool is boiled first with the dye, and when it has absorbed as much of the colour as possible the mordant is added to the same bath, thus fixing the colour.
A separate bath can be used for each of these processes, in which case each bath can be replenished and used again for a fresh lot of wool.
3rd.--The wool is boiled with the mordant and dye in the same bath together. The colour, as a rule, is not so fast and good as with a separate bath, though with some dyes a brighter colour is obtained.
4th.--The wool is mordanted, then dyed, then mordanted again. This method is adopted to ensure an extremely fast colour. The mordant should be used rather sparingly.
SILK
There are two kinds of silk (1) _raw silk_ (reeled silk, thrown silk, drawn silk), and (2) _waste silk_ or spun silk.
Raw silk is that directly taken from the coc.o.o.ns. Waste silk is the silk from coc.o.o.ns that are damaged in some way so that they cannot be reeled off direct. It is, therefore, carded and spun, like wool or cotton.
Silk in the raw state is covered with a silk gum which must be boiled off before dyeing is begun. It is tied up in canvas bags and boiled up in a strong solution of soap for three or four hours until all the gum is boiled off. If it is a yellow gum, the silk is wrought first in a solution of soft soap at a temperature just below boiling point for about an hour, then put into bags and boiled. After boiling, the soap is well washed out.
Generally speaking, the affinity of silk for dyes is similar but weaker in character to that of wool. The general method for dyeing is the same as for wool, except, in most cases, lower temperatures are used in the mordanting. In some cases, soaking in a cold concentrated solution of the mordant is sufficient. The dyeing of some colours is also at low temperature.
COTTON
Cotton is the down surrounding the seeds in pods of certain shrubs and trees growing in tropical and semi-tropical countries. First introduced into Europe by the Saracens, it was manufactured into cloth in Spain in the early 13th century. Cotton cloth was first made in England in the early 17th century.
The colour of cotton varies from deep yellow to white. The fibre differs in length, the long stapled being the most valued. It is difficult to dye and requires a special preparation.
A few of the natural dye stuffs are capable of dyeing cotton direct, without a mordant, such as Turmeric, Barberry bark, safflower, annatto. For other dyes cotton has a special attraction, such as catechu.
LINEN
Linen is flax, derived from the decomposed stalks of a plant of the genus Linum.
It grows chiefly in Russia, Belgium, France, Holland and Ireland. The plants after being gathered are subjected to a process called "retting" which separates the fibre from the decaying part of the plant. In Ireland and Russia this is usually done in stagnant water, producing a dark coloured flax. In Belgium, Holland, and France, retting is carried out in running water, and the resulting flax is a lighter colour. Linen is more difficult to dye than cotton, probably on account of the hard nature of the fibre. The same processes are used for dyeing linen as for cotton.