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This question group is public and is used in 24 tests.

Author: szeiger
No. Questions: 10
Created: Jul 11, 2014
Last Modified: 8 years ago

Vegetable Dyes

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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 principal fleeces are:

Lambs, 3 to 6 months growth, the finest, softest and most elastic wool.[Pg 2]

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.


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.


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[Pg 3] 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 140°F. 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 principal 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.


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 cocoons. Waste silk is the silk from cocoons 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[Pg 4] 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 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 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.[Pg 5]

To Bleach Linen—(For 13 to 15 yards linen). Boil 1/2 lb. soap and 1/2 lb. soda in a gallon of water. Put it in a copper and fill up with water, leaving room for the linen to be put in. Put in the linen and bring to the boil. Boil for 2 hours, keeping it under the water and covered. Stir occasionally. Then spread out on the grass for 3 days, watering it when it gets dry. Repeat this boiling and grassing 3 weeks. The linen is then pure white.
Grade 12 Making Inferences and Drawing Conclusions CCSS: CCRA.R.1, RI.11-12.1
Grade 12 Supporting Details CCSS: CCRA.R.3, RI.11-12.3
Why shouldn't wool be washed until it is ready to be dyed?
  1. Because it will stretch
  2. Because it contains grease that repels moths
  3. Because it will hold its color better
  4. Because it must take time to rid itself of grease
Grade 12 Making Inferences and Drawing Conclusions CCSS: CCRA.R.1, RI.11-12.1
Based on the information in the passage, which type of wool, when purchased, should be washed and dyed right away?
  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.
  4. None of the above
Grade 12 Supporting Details CCSS: CCRA.R.3, RI.11-12.3
Grade 12 Compare and Contrast CCSS: CCRA.R.3, RI.11-12.3
What do all four fabrics have in common?
  1. They all are hard to dye.
  2. They all come from mammals.
  3. They all must be boiled or washed.
  4. They all hold the color of the dye well.