"Notwithstanding the very great facility of dyeing wool blue, when the blue vat is once prepared, it is far otherwise with regard to the preparation of this vat, which is actually the most difficult operation in the whole art of dyeing."—Hellot.

INDIGO

Indigo is the blue matter extracted from a plant, Indigofera tinctoria & other species, growing in Asia, South America and Egypt. It reaches the market in a fine powder, which is insoluble in water. There are two ways of dyeing with indigo. It may be dissolved in sulphuric acid or oil of vitriol, thereby making an indigo extract. This process was discovered in 1740. It gives good blue colours, but is not very permanent. Darker colours by this method are more permanent than the paler ones. It does not dye cotton or linen.

The other method is by the indigo vat process, which produces fast colours, but is complicated and difficult. In order to colour with indigo, it has to be deprived of its oxygen. The deoxydised indigo is yellow, and in this state penetrates the woollen fibre; the more perfectly the indigo in a vat is deoxydised, the brighter and faster will be the colour. For the dyeing of wool, the vats are usually heated to a temperature of 50°C. Cotton and linen are generally dyed cold.

Hellot says "when the vat, of whatsoever kind it be, is once prepared in a proper state, there is no difficulty in dyeing woollens or stuffs, as it is requisite only to soak them in clean warm water, to wring them, and then to immerse them in the vat, for a longer or shorter time, according as you would have the colour more or less deep. The stuff should be from time to time opened, that is to say, taken out and wrung over the vat and exposed to the air for a minute or two, till it becomes blue. For let your vat be what it will, the stuff will be green when taken out and will become blue when exposed to the air. In this manner it is very proper to let the colour change before you immerse your stuffs a second time, as you are thereby better enabled to judge whether they will require only one or several dips."—"The Art of Dyeing Wool," by Hellot.

The colour of the blue is brightened by passing the wool through boiling water after it comes out of the dye. Indigo is a substantive dye and consequently requires no mordant.

[13] 1). To Make Extract of Indigo.—

Put 2 lbs. of oil of vitriol into a glass bottle or jar, stir into it 8 oz. of powdered indigo, stirring briskly for ½ hour, then cover up and stir 4 or 5 times a day for a few days, then add a little powdered chalk to neutralise the acid. It should be added slowly, little by little, as the chalk makes the acid bubble up. Keep it closely corked.

2). To Make Extract of Indigo.—

4 oz. sulphuric acid, ½ oz. finely ground Indigo. Mix like mustard, and leave to stand over-night. Prepare the wool by mordanting with 5 oz. alum to 1 lb. wool. Boil for ½ hour and dye without drying.

3). To Dye Wool with Indigo Extract

For 4 to 6 lbs. of wool. Stir 2 to 3 oz. of Indigo extract into the water of the dye bath. The amount is determined by the depth of shade required. When warm, enter the wool, and bring slowly to boiling point (about ½ hour) and continue boiling for another ½ hour. By keeping it below boiling point while dyeing, better colours are got, but it is apt to be uneven. Boiling levels the colour but makes the shade greener. This is corrected by adding to the dye bath a little logwood, 10 to 20 per cent. This should be boiled up separately, strained, and put in the bath before the wool is entered. Too much should be avoided however, as it dims the colour. It can be done in the same bath, but better results are got by separate baths. Instead of logwood a little madder is sometimes used; also Cudbear or Barwood.

4). To Dye Silk with Indigo Extract.

Dye at a temperature of 40 to 50°C. in a bath with a little sulphuric acid and the amount of indigo as is needed for the colour. Another method is to mordant the silk first with alum by steeping it for 12 hours in a solution of 25 per cent. and then, without washing, to dye with the Indigo Extract and about 10% of alum added to the dye bath. By this means compound colours can be made by the addition of cochineal, for purple, or old Fustic, Logwood, etc., for greys, browns and other colours.

5). Saxon Blue.—

Put into a glazed earthen pot 4 lbs. of good oil of vitriol with 12 oz. of choice Indigo, stir this mixture very hastily and frequently in order to excite a fermentation. It is customary with some Dyers to put into this composition a little antimony or salt-petre, tartar, chalk, alum and other things, but I find it sufficient to mix the oil and Indigo alone, and the colours will be finer, for those neutral salts destroy the acid of the vitriol and sully the colour. In 24 hours it is fit for use. Then a copper of a good size is to be filled with fair water (into which one peck of bran is put in a bag) and made pretty warm, the bran after yielding its flower must be taken out, and the Chymie, (Indigo Extract) mixed well with water in a Piggin, (a small pot) is put in according to the shade required, having first put in a hand-ful of powdered tartar; the cloth is to be well wet and worked very quick over the winch (stick on which it is hung) for half an hour. The liquor must not be made hotter than for madder red (just under boiling point). The hot acid of the vitriol would cause the blue to incline to green if too much heat was given. (From an old Dye Book).

6). To Make up a Blue Vat.—

Take 1 lb. Indigo thoroughly ground, put this into a deep vessel with about 12 gallons of water, add 2 lbs. copperas, and 3 lbs. newly slaked lime, and stir for 15 minutes. Stir again after 2 hours and repeat every 2 hours for 5 or 6 times. Towards the end, the liquor should be a greenish yellow colour, with blackish veins through it, and a rich froth of Indigo on the surface. After standing 8 hours to settle, the vat is fit to use.

7). Turquoise for Wool.—

Mordant with alum. For a pale shade use 1 teaspoonful of Indigo Extract (see No. 2) for 1 lb. of wool. Boil ¼ hour.

8). Blue for Wool. (Highlands).

Take a sufficiency of Indigo. (For medium shade about 1 oz. to every pound of wool). Dissolve it in about as much stale urine (about a fortnight old) as will make a bath for the wool. Make it lukewarm. Put in the wool and keep it at the same temperature till the dyeing is done. For a deep navy blue it will take a month, but a pale blue will be done in 3 or 4 days. Every morning and evening the wool must be taken out of the dye bath, wrung out and put back again. The bath must be kept covered and the temperature carefully attended to. Some add a decoction of dock roots the last day, which is said to fix the blue. The wool must then be thoroughly washed. This is a fast dye.

9). Indigo Vat. (For small dyers).

Add to 500 litres of stale urine 3 to 4 kilos of common salt and heat the mixture to 50° to 60°C., for 4 to 5 hours with frequent stirring, then add 1 kilo of madder, 1 kilo of ground Indigo, stir well, and allow to ferment till the Indigo is reduced.

10). Saxon Blue. (Berthollet).

Prepare the wool with alum and tartar. A smaller or greater proportion of the Indigo solution is put into the bath, (1 part of Indigo with 8 parts of sulphuric acid, digested for 24 hours), according to the depth of shade wished to be obtained. For deep shades it is advantageous to pour in the solution by portions, lifting out the wool from the bath while it is being added. The cold bath acts as well as the hot.

11). The Cold Indigo Vat with Urine.

Take 4 lbs. of powdered Indigo and put it into a gallon of vinegar, leaving it to digest over a slow fire for 24 hours. At the end of this time the Indigo should be quite dissolved. If not dissolved pound it up with some of the liquor adding a little urine. Put into it ½ lb. madder, mixing it well. Then pour it into a cask containing 60 gallons of urine (fresh or stale). Mix and stir the whole together; this should be done morning and evening for 8 days or until the surface becomes green when stirred, and produces froth. It may be worked immediately without any other preparation than stirring it 3 or 4 hours before-hand. This kind of vat is extremely convenient, because when once prepared it remains so always until it is entirely exhausted. According as you would have your vat larger or smaller you reduce or enlarge the amount of the ingredients used in the same proportion as the original. This vat is sooner prepared in summer than in winter.

12). Indigo Vat on a small scale for Woollens and Cottons.—

Have a strong 9 gallon cask, put into it 8 gallons of urine, have a 4 quart pickle jar, into which put 1 lb. ground Indigo and 3 pints of best vinegar; put the jar into a saucepan filled with water, and make it boil well for 2 hours, stirring it all the time. Let it stand in a warm place for 3 days, then pour it into the cask; rake it up twice a day for a month. It must be covered from the air.

13). Blue Vat for Woollens.—

For every 20 gallons of water add 5 oz. ground Indigo, 8 oz. of potash, 3 oz. madder, and 4 oz. bran. Keep the solution at 140°F.; after 24 hours the whole will have begun to ferment, then add 2 oz. madder, stir and allow the whole to settle, after which the vat is ready for use.

14). To Dye Indigo Blue. Urine Vat.—

Prepare vat as follows:—To 3½ gallons of stale urine add 4½ oz. of common salt, and heat the mixture to 125°F. (as hot as the hand can bear). Keep at this heat for 4 to 5 hours, frequently stirring, then add 1¼ oz. thoroughly ground Indigo and 1¼ oz. Madder, stir well and allow to ferment till the Indigo is reduced. This is recognized by the appearance of the vat, which should be of a greenish yellow colour, with streaks of blue. Allow the vat to settle, when you can proceed with dyeing. Process of dyeing the same as in No. 15.

15). To Dye Indigo Blue.—Potash Vat.—

Into a pot 3 parts full of water put 1½ oz. Madder and 1½ oz. bran. Heat to nearly boiling, and keep at this heat for 3 hours. Then add 5 oz. Carbonate of Potash; allow Potash to dissolve and let the liquor cool down till luke-warm. Then add 5 oz. thoroughly ground Indigo, stir well and leave to ferment for two days, occasionally stirring, every 12 hours or so. Wool dyed in this vat must be thoroughly washed after the colour is obtained.

Process of Dyeing.—Into a vat prepared as above, dip the wool. Keep it under the vat liquor, gently moving about a sufficient time to obtain the colour required. A light blue is obtained in a few seconds, darker blues take longer. Take out wool, and thoroughly squeeze out of it all the dye liquor back into the vat. Spread out the wool on the ground, exposed to the air till the full depth of colour is developed. The wool comes out of the vat a greenish shade, but the oxygen in the air darkens it, through oxydation, to indigo blue. The wool should now be washed in cold water with a little acid added to it, and again thoroughly rinsed and dried.

16). Blue Vat for Cotton.—

In a clean tub put 10 pails of water, slacken 1 bushel of lime into it, and cover while slackening; put 6 lbs. ground Indigo in a pot and mix it into a paste with hot water and then put 4 pails of boiling water on to it, stir it, cover it, and leave it. In another pot, put 20 lbs. copperas, pour 4 pails of water on this, stir it and leave it covered. Pour 4 pails of water on the top of the lime that is slackening, rake it up well and put in the melted copperas; rake it well and put in the Indigo; stir well and leave covered for a couple of days, stirring occasionally. Half fill a new vat with the mixture. Rake it well and while you are raking, fill it up with clean water, continue raking for an hour. Cover it over; it can be used the next day. This is a colour that never washes out.

17). Gloucestershire Indigo Vat.

Size 5 feet over the top: 7 feet deep, 6 to 7 feet at the bottom.

Take ½ cwt. bran, ¼ peck lime and 40 lbs. indigo. Warm up to 180 to 200°F., rake it 4 times a day. If it ferments too much add more lime: if not enough, more bran. An experienced eye or nose will soon tell when it is ripe or fit to use, which should be in about 3 days. Regulate the strength of the vat from time to time to the colour required. No madder or woad is used when much permanency is wanted.

18). Cold Indigo Vat for Dyeing Wool, Silk, Linen and Cotton.

1 part Indigo, 3 parts good quicklime, 3 parts English vitriol, and 1½ parts of orpiment. The Indigo is mixed with water, and the lime added, stirred well, covered up, and left for some hours. The powdered vitriol is then added, and the vat stirred and covered up. After some hours the orpiment powder is thrown in and the mixture is left for some hours. It is then stirred well and allowed to rest till the liquid at the top becomes clear. It is then fit for dyeing.

WOAD

Woad is derived from a plant, Isatis tinctoria, growing in the North of France and in England. It was the only blue dye in the West before Indigo was introduced from India. Since then woad has been little used except as a fermenting agent for the indigo vat. It dyes woollen cloth a greenish colour which changes to a deep blue in the air. It is said to be inferior in colour to indigo but the colour is much more permanent. The leaves when cut are reduced to a paste, kept in heaps for about fifteen days to ferment, and then formed into balls which are dried in the sun; these have a rather agreeable smell and are of a violet colour. These balls are subjected to a further fermentation of 9 weeks before being used by the dyer. When woad is now used it is always in combination with Indigo, to improve the colour. Even by itself, however, it yields a good and very permanent blue.

It is not now known how the ancients prepared the blue dye, but it has been stated (Dr. Plowright) that woad leaves when covered with boiling water, weighted down for half-an-hour, the water then poured off, treated with caustic potash and subsequently with hydrochloric acid, yield a good Indigo blue. If the time of infusion be increased, greens and browns are obtained. It is supposed that woad was "vitrum," the dye with which CÆsar said almost all the Britons stained their bodies. It is said to grow near Tewkesbury, also Banbury. It was cultivated till quite lately in Lincolnshire. There were four farms in 1896; one at Parson Drove, near Wisbech, two farms at Holbeach, and one near Boston. Indigo has quite superseded it in commerce.[14]

"It is like the Indigo plant, but less delicate and rich. It is put in vats with Indigo and madder to dye a never-fading dark blue on wool, and was called woad-vats before Indigo was known." (Thomas Love). And again "Woad, or what is much stronger, pastel, always dyed the blue woollens of Europe until Indigo was brought over here."

Bancroft says "Woad alone dyes a blue colour very durable, but less vivid and beautiful than that of Indigo."

LOGWOOD

(Bois de CampÊche, Campeachy Wood)

Logwood is a dye wood from Central America, used for producing blues and purples on wool, black on cotton and wool, and black and violet on silk. It is called by the old dyers, one of the Lesser Dyes, because the colour loses all its brightness when exposed to the air. But with proper mordants and with careful dyeing this dye can produce fast and good colours. Queen Elizabeth's government issued an enactment entirely forbidding the use of logwood. The act is entitled "An Act for the abolishing of certeine deceitful stuffe used in the dyeing of clothes," and it goes on to state that "Whereas there hath been brought from beyond the seas a certeine kind of stuff called logwood, alias blockwood, wherewith divers dyers," etc., and "Whereas the clothes therewith dyed, are not only solde and uttered to the great deceit of the Queene's loving subjects, but beyond the seas, to the great discredit and sclaunder of the dyers of this realme. For reformation whereof, be it enacted by the Queene our Soveraygne Ladie, that all such logwood, in whose handes soever founde, shall be openly burned by authoritie of the maior." The person so offending was liable to imprisonment and the pillory. This is quoted from "The Art of Dyeing," by James Napier, written in 1853. He goes on to say, "Upwards of eighty years elapsed before the real virtues of this dyeing agent were acknowledged; and there is no dyewood we know so universally used, and so universally useful." The principal use for logwood is in making blacks and greys. The logwood chips should be put in a bag and boiled for 20 minutes to ½ hour, just before using. "Logwood is used with galls and copperas for the various shades of greys, inclining to slate, lavender, dove, and lead colour, etc. For this purpose you fill a cauldron full of clean water, putting into it as much nut galls as you think proper. You then add a bag of logwood, and when the whole is boiled, having cooled the liquor, you immerse the stuff, throwing in by degrees some copperas, partly dissolved in water."—Hellot. Hellot is very scornful of logwood, naming it as one of the lesser dyes, and not to be used by good dyers.

RECIPES FOR DYEING with LOGWOOD

1). Black for Cotton.—

After washing, work the cotton in a cold infusion of 30% to 40% of Sumach, or its equivalent in other tannin matter[15] (ground gall nuts, myrobalans, etc.) and let steep over-night. Squeeze out and without washing pass through a bath containing a diluted solution of lime water, or soda. Work in a cold solution of copperas for ½ hour, then back into the soda for a ¼ hour at a temperature of 50° to 60°C. Then wash. Dye in a freshly made bath of logwood with a small proportion of old Fustic or Quercitron Bark. The cotton is introduced into the cold dye liquor and the temperature gradually raised to boiling. Boil for ½ an hour. After dyeing, the cotton should be passed through a warm solution of Bichromate of Potash. (5 grains per litre). It is then washed and worked in a warm solution of soap and dried. More Fustic makes a greener black.

When catechu is the tanning matter employed, the cotton should be worked in a boiling decoction of it and allowed to steep till cold.

2). Grey Drab for Wool.

(10 lbs.) Dissolve ½ oz. Bichromate of Potash in water, and then boil for ½ hour; lift the wool and add 1 oz. logwood: boil for ½ hour. Lift out, wash and dry.

3). Logwood Grey on Cotton.

The cotton is worked in a weak decoction of logwood at 40° to 50°C., and then in a separate bath containing a weak solution of ferrous sulphate or Bichromate of Potash. Wash.

4). Green Black for Wool.—

Mordant wool with 3% Bichromate of Potash and 1% Sulphuric acid (or 4% Tartar) for 1 to 1½ hours. Then wash and dye with 35% to 50% of Logwood. This gives a blue black. It is greened by adding 5% old Fustic to the dye bath. The more Fustic the greener the black becomes. If 3% to 4% alum is added to the mordanting bath, a still greener shade is obtained. Sulphuric acid in the mordant produces a dead looking blue black. Tartar yields a bright bluish black.

5). Logwood Blue for Wool.

Mordant the wool for 1 to 1½ hours at 100°C., with 4% alum and 4 to 5% cream of Tartar. Wash well and dye for 1 to 1½ hours at boiling point with 15 to 30% logwood and 2 to 3% chalk. This colour is not very fast, but can be made faster by adding 1 to 3% bichromate of potash and 1% sulphuric acid. The brightest logwood blues are obtained by dyeing just below boiling point. Long boiling dulls the colour.

6). Green Black for Wool.

Mordant with 2% Chrome and 25% sulphuric acid. Boil 1½ hours and leave overnight. Dye with 40% logwood and 10% Fustic. Boil 1 hour.

7). Logwood Blue for Wool.

Chrome 1%, Alum 3%, Tartar 1½%. Boil 1½ hours and leave over-night. Dye with logwood 20% and Cudbear 1%. Boil one hour, then throw in 20 quarts of single muriate of tin, diluted with 20 to 30 gallons of water. Immerse 15 minutes and wash.

8). Fast Purple for Cotton.

(For 20 lbs. cotton.) Mordant with copperas. Wash slightly; then a bath of muriate of tin. Dye with 4 to 5 lbs. logwood.

9). Fast Black on Wool.—

Put wool into a strong logwood bath, the stronger the better, and boil for 1 hour. Take out and drain, and put into a Bichromate of Potash bath and keep at 150°F. for about 5 minutes. Then a bath of Fustic or Quercitron. After which wash well in cold water.

10). Black for Cotton.—

(For 10 lbs.) Steep cotton in hot decoction of 3 lbs. Sumach and let stay over night. Wring out and work for 10 minutes through lime water: then work for ½ hour in a solution of 2 lbs. copperas. It may be either washed from this, or worked again through lime water for 10 minutes. Dye for ½ hour in a warm decoction of 3 lbs. logwood adding ½ pint chamber lye. Take out cotton and add to the same bath 2 oz. copperas. Work 10 minutes, then wash and dry. 1 lb. Fustic is added for jet black.

11). Fast Black for Woollens.—

(For 50 lbs.) Mordant with 2 lbs. chrome, 1 lb. Tartar, 1 quart Muriate of Tin. Boil 1 hour and wash well. Dye with 25 lbs. logwood and 3 lbs. Fustic. Boil 30 minutes. Take out and add 1 pint Vitriol. Return for 10 minutes, wash and dry.

12). Jet Black for Silk.

(For 50 lbs.) Mordant in hot solution of Nitro-Sulphate of Iron at 150°F., work for ½ hour. Wash well, then boil up 18 lbs. Fustic. Put off the boil, enter silk and work for 30 minutes. Take out. Boil 16 lbs. logwood, put off the boil and decant the liquor into fresh bath, add 1 lb. white soap, enter and work from 30 to 40 minutes. Wash well.

13). Lavender for Wool.

(For 6¼ lbs.) Mordant with 3 oz. Bichromate of Potash, for 45 minutes and wash. Dye with 2 oz. madder, 1 oz. logwood. Enter the wool, raise to the boil and boil for 45 minutes. The proportion of logwood to madder can be so adjusted as to give various shades of claret to purple.

14). Black for Wool.

Mordant 6¼ lbs. wool with 4 oz. Chrome. Boil for 45 minutes. Dye with 50 oz. logwood, 1 oz. Fustic. Raise to boil and boil for 45 minutes.

15). Fast Chrome black for Wool.

(For 40 lbs. wool.) Dissolve 3 lbs. copperas and boil for a short time. Then dip the wool in this for ¾ hour, airing frequently. Take out wool and make dye with 24 lbs. logwood. Boil for ½ hour. Dip ¾ hour, air wool, dip ¼ hour longer and then wash in strong soap suds.

16). Light silver drab for Wool.

(For 50 lbs. wool). ½ lb. logwood, ½ lb. alum. Boil well and enter wool and dip for 1 hour.

17). A fast Logwood Blue for Wool.

(Highland recipe). Mordant with 3% Bichromate of Potash and boil wool in it for 1½ hours. Wash and dry wool. Make a bath of 15 to 20% logwood with about 3% chalk added to it. Boil the wool for 1 hour, wash and dry. The wool can be greened by steeping it all night in a hot solution of heather, or boiling it in heather till the desired tint is obtained.

18). Green Black for Wool.

(For 50 lbs. wool). Boil 20 minutes with 1 lb. chrome. Dye with 20 lbs. Fustic, 8 lbs. logwood. Boil for ½ hour.

19). Slate Purple.

(For 80 lbs. yarn). Mordant with 2 lbs. chrome for 20 minutes. Dye with 10 lbs. logwood & 1 lb. Cudbear. Boil for ½ hour.

20). Raven Grey for Wool.

(For 60 lbs.) Dissolve 8 oz. Alum and work the wool very quickly for ½ hour at boiling heat; then take it out and add to the same liquor 3 or 4 lbs. copperas, & work it at boiling heat for ½ hour. Then wash. In another copper, boil 1 pailfull of logwood chips for 20 minutes. Put the wool into this for ½ hour; then return it into the alum and copperas for 10 to 15 minutes.

21). Dark Red Purple with Logwood for Wool.—(For 2½ lbs.)

Mordant with 10 oz. alum and 2½ oz. cream of tartar for 1 hour. Let cool in the mordant, then wring out and put away for 4 or 5 days in a linen (or other) bag in the dark.

Dye with 1 lb. logwood, and ½ lb. madder. Boil up the logwood and madder in a separate bath and pour through a sieve into the dye bath. Enter the wool when warm and bring to boil. Boil from ½ hour to 1½ hours. Wash thoroughly.

22). Violet with Logwood for Silk.

The silk is washed from the soap and drained. For every pound of silk, dissolve in cold water 1 oz. verdigris; when it is well mixed with the water, the silk is immersed and kept in this liquor for an hour. This does not give colour. It is then wrung & aired. A logwood liquor is then made; the silk dipped in it when cold; it takes a blue colour sufficiently dark. The silk is taken out and dipped in a clear solution of alum; it acquires a red which produces a violet on the silk just dyed blue. The quantity of alum is undetermined; the more alum the redder the violet. The silk is then washed.

23). Ordinary Logwood Purple for Wool.

(For 1 lb.) Mordant wool with ¼ lb. alum and ½ oz. tartar for 1 hour; wring out and put away in a bag for some days. Dye with ¼ lb. logwood for 1 hour.