Part 10 (1/2)

(5) JADE GREEN (1 lb)

Mordant with 1/3 oz Cream of Tartar and 4 oz Alum for 1/2 hour Take out wool and air Cool bath a little and add half the a to shade of green required, 1/2 oz indigo extract ood colour) Enter wool and stir rapidly for 5Take out wool Mix in the rest of the indigo extract Enter wool and boil for 10 minutes Take out wool Throay a quarter of the water and add some with 3/4 oz

fustic extract Enter wool and boil for 1/2 hour to an hour

CHAPTER X

THE DYEING OF COTTON

The dyeing of cotton is difficult with the natural dye stuffs, there are only a few colours which can be said to be satisfactory The fastest known in earlier days was Turkey red, a long and difficult process with madder and not very practical for the sin in India where it is still used; red Indian cotton is one of the fastest colours known Catechu is another excellent cotton dye used for various shades of brown, grey and black A cold indigo vat is used for blue, Indigo Extract is not used Yellows can be got eld, flavin, tur attraction), and fustic Great care is to be taken in dyeing yellow as it is not very fast to light Greens o vat and then with a yellow recipe, purples froreens are unsatisfactory, and not suitable to the vegetable dyer

BOILING OUT

Before dyeing cotton in the raw state, or in yarn spun direct from the raw state, it must be boiled for several hours to extract its natural impurities For dark colours water alone ht colours a weak solution of carbonate of soda, 5; or of caustic soda, 2, should be used

MORDANTS

_Aluht of cotton) is dissolved in hot water with carbonate of soda crystals, or other alkali (1/4 weight of alum); work cotton in the solution, steep for several hours or overnight Then ash Alue 56) h a fixing solution of so with alum, the cotton is often prepared with tannic acid

_Iron_ Iron is usually e is steeped in a cold solution of theblack, when the cotton, after being prepared with tannin, is steeped in a cold solution of Iron This process by itself gives a dark colour before any dye is used

_Tin_ Tin is rarely used alone as a htens the colour in combination with other mordants

_Chrome_ Chrome is used for browns and other colours with Catechu

After boiling in a solution of the dye stuff, boil a short ti matter of the Catechu

_Copper_ Copper is sometimes added in small quantities to the dye bath for brown or yellow to vary the shade

_Tannin (Tannic acid)_ Cotton and linen strongly attract tannin and when prepared with it they are able to retain dyes permanently Cotton saturated with tannin attracts the dye stuff more rapidly, and holds it Tannic acid is the best tannin foras it is the purest and is free fro ht shades But for dark shades, substances containing tannic acid are used, such as _sualls_, _chestnut_ (8 to 10 per cent tannin), _catechu_

Cotton and linen are prepared with tannin after they have been through the required cleansing, and, if necessary, bleaching operations A bath is prepared with 2 to 5 per cent of tannic acid of the weight of the cotton, and a sufficient quantity of water For dark shades, 5 to 10 per cent should be used The bath is used either hot or cold It should not be above 60C The cotton is worked in this for some time, and then left to soak for 3 to 12 hours, while the bath cools It is then wrung out and slightly washed

The following gives the relative proportions of the various substances containing tannin:--1 lb tannic acid _equals_ 4 lbs sumach, 18 lbs

alls

_Examples from various recipes_:

For 10 lbs cotton use 12 ozs tannic acid

” 50 ” ” ” 10 lbs sumach

” 40 ” ” ” 10 lbs ”

” 20 ” ” ” 2 lbs yellow (or black) catechu

” 20 ” ” ” 3 lbs catechu with 3 ozs blue vitriol