Alectoria jubata.Horsehair Lichen, Rock hair. On fir trees in England. Pale greenish brown.Borrera flavicans.Yellow borrera. On trees in Germany. Gamboge yellow.Cetraria Islandica.Iceland moss. Iceland heaths and hills. It yields a good brown to boiling water, but this dye appears only to have been made available in Iceland.Cetraria juniperina.En-mossa. On trees in Scandinavia.Evernia flavicans.Wolf's-bane evernia. On trees in Scandinavia. Gamboge yellow.Gyrophora cylindrica.Cylindrical gyrophora. On rocks in Iceland. Greenish brown. Also G. deusta.G. deusta.Scorched-looking gyrophora. On rocks in Scandinavia. Linnaeus states that it furnishes a paint called "Tousch", much used in Sweden.Lecanora candelaria.Ljus mässa. On trees in Sweden.Lecidea atro-virens.Map lichen. On rocks, Scandinavia.Lepraria chlorina.Brimstone coloured lepraria. Scandinavia, on rocks.L. Iolithus.Viol-mässa. Sweden, on stones. Gives stones the appearance of blood stains.Parmelia omphalodes.In Scandinavia and Scotland. Withering asserts it yields a purple dye, paler, but more permanent, than orchil; which is prepared in Iceland by steeping in stale lye, adding a little salt and making it up into balls with lime.P. parietina.Common yellow wall lichen, Wäg-mässla Wag-laf. England and Sweden, on trees, rocks, walls, palings. Used to dye Easter eggs. Used in Sweden for wool dyeing.P. physoides.Dark crottle, Bjork-laf. Found in Sweden, Scotland and Scandinavia, on rocks and trees.Sticta pulmonacea.Oak lung, Lungwort, Aikraw Hazelraw, Oak-rag, Hazel crottle, Rags. Found on trees in England, Scotland, North of Ireland, Scandinavia. It dyes wool orange and is said to have been used by the Herefordshire peasantry to dye stockings brown. Some species yield beautiful saffron or gamboge coloured dyes, e.g.S. flava crocata, aurata.S. scrobiculata.Aik-raw, Oak rag. Found on trees in Scotland and England.
Alectoria jubata.Horsehair Lichen, Rock hair. On fir trees in England. Pale greenish brown.
Borrera flavicans.Yellow borrera. On trees in Germany. Gamboge yellow.
Cetraria Islandica.Iceland moss. Iceland heaths and hills. It yields a good brown to boiling water, but this dye appears only to have been made available in Iceland.
Cetraria juniperina.En-mossa. On trees in Scandinavia.
Evernia flavicans.Wolf's-bane evernia. On trees in Scandinavia. Gamboge yellow.
Gyrophora cylindrica.Cylindrical gyrophora. On rocks in Iceland. Greenish brown. Also G. deusta.
G. deusta.Scorched-looking gyrophora. On rocks in Scandinavia. Linnaeus states that it furnishes a paint called "Tousch", much used in Sweden.
Lecanora candelaria.Ljus mässa. On trees in Sweden.
Lecidea atro-virens.Map lichen. On rocks, Scandinavia.
Lepraria chlorina.Brimstone coloured lepraria. Scandinavia, on rocks.
L. Iolithus.Viol-mässa. Sweden, on stones. Gives stones the appearance of blood stains.
Parmelia omphalodes.In Scandinavia and Scotland. Withering asserts it yields a purple dye, paler, but more permanent, than orchil; which is prepared in Iceland by steeping in stale lye, adding a little salt and making it up into balls with lime.
P. parietina.Common yellow wall lichen, Wäg-mässla Wag-laf. England and Sweden, on trees, rocks, walls, palings. Used to dye Easter eggs. Used in Sweden for wool dyeing.
P. physoides.Dark crottle, Bjork-laf. Found in Sweden, Scotland and Scandinavia, on rocks and trees.
Sticta pulmonacea.Oak lung, Lungwort, Aikraw Hazelraw, Oak-rag, Hazel crottle, Rags. Found on trees in England, Scotland, North of Ireland, Scandinavia. It dyes wool orange and is said to have been used by the Herefordshire peasantry to dye stockings brown. Some species yield beautiful saffron or gamboge coloured dyes, e.g.S. flava crocata, aurata.
S. scrobiculata.Aik-raw, Oak rag. Found on trees in Scotland and England.
FOOTNOTES:[D]From an article by Dr. Lauder Lindsay on "The Dyeing Properties of Lichens."The Edinburgh Philosophical Journal, July to October, 1855.
[D]From an article by Dr. Lauder Lindsay on "The Dyeing Properties of Lichens."The Edinburgh Philosophical Journal, July to October, 1855.
[D]From an article by Dr. Lauder Lindsay on "The Dyeing Properties of Lichens."The Edinburgh Philosophical Journal, July to October, 1855.
Indigo is the blue matter extracted from a plantIndigofera tinctoriaand 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 are more so than the paler. 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 deoxidized indigo is yellow and in this state penetrates the woollen fibre; the more perfectly the indigo in a vat is deoxidized, the brighter and faster will be the colour. For wool dyeing the vats are heated to a temperature of 50°C. Cotton and linen are generally dyed cold.
1 lb. oil of vitriol (pure, not commercial).2 oz. finely ground Indigo.1/2 oz. precipitated chalk.
Mix a little of the indigo with a small quantity of oil of vitriol, add a little chalk and stir well. Go on mixing gradually till all is used up. This should take an hour or two. Stir a few times each day for 4 or 5 days, adding about 1/2 oz. more of chalk by degrees. It is best mixed in a glass stoppered bottle or jar, and stirred with a glass rod. It must be kept from the air.
Mordant[E]25% Alum. Stir 2 to 3 ozs. Indigo extract into the water of dye bath. The amount is determined by the depth of shade required. When warm, enter the wool and bring slowly to boiling point (about 1/2 an hour) and continue boiling for another 1/2 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 which should be boiled up separately, strained, and put in bath before the wool is entered; too much logwood dims the colour. Instead of logwood a little madder is sometimes used; also Cudbear or Barwood.
To 2 quarts of water add 1/4 lb. lime, and make hot. Then add 1 oz. indigo pounded up with a little of the lime water; let it stand and get warmer. Pound up 1/2 oz. tin,Stannous Chloride, in a little lime water and add, together with 1/2 oz. zinc. Add more lime water or tin according to the state of the vat. There should be a streaky scum on the surface, and the water underneath clear with a green tinge. Pearl ash can be used instead of lime.
2 ozs. powdered indigo.7 fluid ozs. Caustic Soda solution (SG 1.2).4 pints Sodium Hydrosulphite (SG 1.1).
The Stock Solution.—Take 2 ozs. of well pounded indigo, with enough warm water (120°F.) to make a paste, andgrindin a pestle and mortar for 10 minutes. Empty into a saucepan, capacity 1 gallon. Take 12 fluid ozs. of water adding gradually 3 ozs. of commercial caustic soda 76 per cent. This will give a solution of SG 1.2, which can be tested with a hydrometer reading from 1000 to 2000, the 1000 representing SG 1 as for water.
Next take 5 pints water, add hydrosulphite slowly, stirring gently until a reading of 1100 is shown (SG 1.1) on the hydrometer. If the hydrosulphite be weighed beforehand and the stock of the same be kept free from damp air, or great heat, for future vats the hydrometer can be dispensed with; it is simply weighed out and added slowly to the water. If added too quickly the hydrosulphite will cake, fall to the bottom and be difficult to dissolve.
To the saucepan containing the indigo (100 per cent) add 7 fluid ozs. of the caustic soda solution, then gradually add 3-1/2 pints of hydrosulphite solution, stirring gently for 15 to 20 minutes. Heat the saucepan to 120°F. and on no account to more than 140°F.—overheating will ruin the Stock Solution—let it stand for half an hour, then test with a strip of glass. This should show a perfectly clear golden yellow colour (turning blue in 45 secs. approx.), free from spots. If dark spots show, this indicates undissolved indigo, therefore gradually add hydrosulphite solution (2-3 fluid ozs.). Wait 15 mins. and test with glass strip; if incorrect continue this every 15 minutes until the glass indicates clear yellow. If the Stock Solution is greenish white and turbid, undissolvedindigo whiteis present. Add then not more than a teaspoonful at a time caustic soda solution until the Stock Solution answers the glass test.
TheDye Vatshould contain about 10 gallons of water heated to hand hot, 120° and not above 140°F. Add 3 ozs. of hydrosulphite solution stirring carefully, let it stand for 20 minutes; this renders harmless any undissolved oxygen. Add a small cupful of the Stock Solution, stir carefully without splashing. The vats should be greenish yellow andshould not feel slimy, an indication of too much caustic. The vat is now ready to dye and is kept at 120° to 140°F.
Between dips add Stock Solution as required, if the vat goes blue and turbid add 3 to 4 fluid ozs. of hydrosulphite and warm up to 140°F. and wait 30 minutes. As a last resort add caustic soda solution very gradually. This should not be required if the Stock Solution is properly prepared.
Start to dye with weak vats, 20 to 40 minute dips, andfinish with stronger vats. The more dips given to obtain a fixed shade, the faster will be the yarn to washing and rubbing. The yarn must be oxidized by exposure to the air for the same length of time as dipped. After the final dip, pass the yarn through a 10 gallon bath of water to which is added 3 ozs. of sulphuric acid, pure or hydrochloric. This neutralizes the caustic used. Wash yarn at least twice in water.
Improvement of Defective Indigo Vat Dyes.
If, after washing until clear, the yarn should rub off badly, there is but one remedy. Wash same in Fuller's earth, and if the shade is then too pale, re-dye. If, through bad management of the vats, the yarn is dull, pass the yarn through a hot bath (100% water, 1% acetic acid) and wash in two waters. If yarn is streaky, take 10 gallons of water at 120°F., 1 oz. of hydrosulphite powder, 2 fluid ozs. liquid ammonia fort. 880, and let yarn lie in same for 60 minutes. Wash in two waters.
The following facts should be carefully noted:—
The Caustic Soda is thealkaliwhich dissolves the Indigo White.
The Hydrosulphitereducesthe Indigotine in the Indigo toIndigo White.
Indigo White is fixed on the yarn as Indigo White and on exposure to the air becomes blue.
The yarn, on removal from the vat, should come out greenish yellow or a greenish blue. The latter is for blue yarn and should not turn blue too quickly (allow 60 seconds at least).
Rest the vats for 1 hour after 3 hours work. Never hurry the vats. It is a good thing to have hydrosulphite slightly in excess as this prevents premature oxidization; too much will strip off the indigo white already deposited on the yarn.
Caustic Soda must always be used with the greatest caution or the yarn will be tendered and ruined.
Finally, unless the yarn is completely scoured it is impossible to obtain a clear colour, or a blue which will not rub off.
The figures given are for Indigo bearing 100% Indigotine, therefore in using vegetable Indigo do not addallthe Caustic or Hydrosulphite, but depend on the glass test rather than on measurements.
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 are 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 nine 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 Caesar 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.
(Bois de Campeche, Campeachy Wood)
Logwood is a dye wood from Central America, used forproducing blues and purples on wool, black on cotton and wool, and black and violet on silk. It is called by old dyers one of the Lesser Dyes, because the colour was said to lose 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 person so offending was liable to imprisonment and the pillory. The principal use for logwood is in making blacks. The logwood chips should be put in a bag and boiled for 20 minutes to 1/2 an hour, just before using.
Mordant the wool for 1 to 1-1/2 hours with 3 per cent Chrome and 1 per cent Sulphuric Acid. Wash and dye in separate bath for 1 to 1-1/2 hours with 50 per cent Logwood. This gives a blue black.
A dead black is got by adding 5 per cent Fustic to the dye bath.
A green black by adding more fustic. Also by adding 3 to 4 per cent Alum to the mordanting bath a still greener shade can be obtained.
A violet black is produced by adding 2 per cent Stannous Chloride to the dye bath and continue boiling for 20 minutes.
Mordant with 3 per cent Bichromate of Potash for 45 minutes and wash. Dye with 2 per cent madder, 1 per cent 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.
(Highland recipe.) Mordant with 3 per cent Bichromate of Potash and boil wool in it for 1-1/2 hours. Wash and dry wool. Make a bath of 15 to 20 per cent logwood with about3 per cent 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 till the desired tint is obtained.
Mordant with 25 per cent Alum for 1/2 hour at boiling heat; then take it out, add to the same liquor 5 per cent copperas, and work it at boiling heat for 1/2 hour. Then wash. In another copper, boil 50 per cent logwood chips for 20 minutes. Put the wool into this for 1/2 hour; then return it into the alum and copperas for 10 to 15 minutes. Wash well.
(2-1/2 lbs.) Mordant with 25 per cent alum and 1 per cent cream of tartar for 1 hour. Let cool in the mordant, then wring out and put away for 4 to 5 days.
Dye with 60 per cent logwood and 25 per cent 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 the boil. Boil from 1/2 hour to 1-1/2 hours. Wash thoroughly in soft water.
(For 1 lb.) Mordant wool with 1/4 lb. alum and 1/2 oz. tartar for one hour; wring out and put away in a bag for some days. Dye with 1/4 lb. logwood for 1 hour.
FOOTNOTES:[E]If the Extract is used alone, a mordant is not essential.
[E]If the Extract is used alone, a mordant is not essential.
[E]If the Extract is used alone, a mordant is not essential.
Kermes, or Kerms, from which is got the "Scarlet of Grain" of the old dyers, is one of the old insect dyes. It is considered by most dyers to be the first of the red dyes, being more permanent than cochineal and brighter than madder. In the 10th century it was in general use in Europe. The reds of the Gothic tapestries were dyed with it, and are very permanent, much more so than the reds of later tapestries, which were dyed with cochineal. Bancroft says "The Kermes red or scarlet, though less vivid, is more durable than that of cochineal. The fine blood-red seen at this time on old tapestries in different parts of Europe, unfaded, though many of them are two or three hundred years old, were all dyed from Kermes, with the aluminous basis, on woollen yarn."
Kermes consists of the dried bodies of a small scale insect,Coccus ilicis, found principally on the ilex oak, in the South of Europe, and still used there.
William Morris speaks of the "Al-kermes or coccus which produces with an ordinary aluminous mordant a central red, true vermilion, and with a good dose of acid a full scarlet, which is the scarlet of the Middle Ages, and was used till about the year 1656, when a Dutch chemist discovered the secret of getting a scarlet from cochineal by the use of tin, and so produced a cheaper, brighter and uglier scarlet."
Kermes is employed exactly like cochineal. It has a pleasant aromatic smell which it gives to the wool when dyed with it.
The dried red bodies of an insect (Coccus Cacti) found in Mexico are named Cochineal.
(For 1 lb. wool.) Mordant with Bichromate of Potash (3%). Dye for 1 to 2 hours with 3 oz. to 6 oz. cochineal. With alum mordant (25%) a crimson colour is got. With tin mordant (10%) a scarlet. With iron mordant (6%) a purplish slate or lilac.
Mordant with 6 per cent Stannous Chloride and 4 per cent Cream of Tartar, boiling 1 hour. Dye with 15 to 20 per cent Cochineal, boil for 1 hour.
Enter in both mordant and dye bath, cool, and raise slowly to the boil. To obtain a yellow shade of scarlet, a small quantity of Flavin, Fustic, or other yellow dye may be added to the dye bath.
(1 lb.) Into the same bath, put 1 oz. tin, 1/8 oz. oxalic acid, 4 oz. cochineal. Enter silk and boil for 1 hour. With less oxalic acid, a less scarlet colour will be obtained.
Mordant with 20 per cent alum or with 15 per cent alum and 5 per cent Tartar. Dye in separate bath, after well washing, with 8 to 15 per cent cochineal. Boil 1 hour. A slight addition of ammonia to the dye bath renders the shade bluer.
(1 lb.) Mordant with Alum. Dye with 2 oz. Madder, 2-1/2 ozs. Cochineal, 1/4 oz. Oxalic Acid and 1/2 oz. tin.
Mordant with 3 ozs. Chrome. Wash. Dye for 2 to 3 hours with 13 ozs. Cochineal, which has been boiled for 10 minutes before entering wool. A tablespoonful of vinegar added to the dye bath helps the colour. Wash thoroughly.
Madder consists of the ground-up dried roots of a plantRubia tinctorum, cultivated in France, Holland and otherparts of Europe, as well as in India. Madder is one of the best and fastest dyes. It is used also in combination with other dyes to produce compound colours. The gradual raising of the temperature of the dye bath is essential in order to develop the full colouring power of madder; long boiling should be avoided, as it dulls the colour. If the water is deficient in lime, brighter shades are got by adding a little ground chalk to the dye bath, 1 to 2 per cent.
Madder is difficult to dye as it easily rubs off and the following points should be noted.
(1). The baths should be quite clean. Rusty baths must not be used.(2). Before dyeing, the wool must be thoroughly washed so as to get rid of all superfluous mordant.(3). A handful of bran to the pound of wool, helps to brighten the colour.(4). The wool should be entered into a tepid dye bath and raised to boiling in 1 hour and boiled for 10 minutes or less.
(1). The baths should be quite clean. Rusty baths must not be used.
(2). Before dyeing, the wool must be thoroughly washed so as to get rid of all superfluous mordant.
(3). A handful of bran to the pound of wool, helps to brighten the colour.
(4). The wool should be entered into a tepid dye bath and raised to boiling in 1 hour and boiled for 10 minutes or less.
Mordant with 1/4 lb. Alum to the pound of wool. Boil for 1 hour, let cool in mordant, wring out and put away in bag for 3 or 4 days. Wash very thoroughly. Then dye with 5 to 8 ozs. madder according to depth of colour required, and a handful of bran for every pound of wool. Enter in cool bath and bring slowly to the boil in an hour or more. Boil for a few minutes.
Mordant with Alum. Dye with 4 to 4-1/2 ozs. madder to lb. wool and a very small quantity of logwood (1/2 oz. to 1 oz. to 3 or 4 lbs. of wool).
(1 lb.) Mordant with 2-1/2 ozs. Copper Sulphate. Dye with 2 ozs. to 4 ozs. Madder according to depth of colour required. For yellow brown add a small quantity of fustic (1/4 oz. to the lb.)
Mordant wool with 3% Chrome (see p.9), wash well and dye with 5 to 8 ozs. madder, bringing slowly to the boil, and boil for 1 hour.
Various shades of brownish red can be got by a mixture of madder, fustic and logwood with a Chrome mordant in varying proportions such as 28 per cent Madder, 12 per cent Fustic, 1 per cent Logwood for a brownish claret. 5 per cent Madder, 4 per cent Fustic, 1/2 per cent Logwood for tan.
Various leguminous trees, including lima, sapan and peach wood, dye red with alum and tartar, and a purplish slate colour with bichromate of potash. Some old dyers use Brazil wood to heighten the red of madder.
CAMWOOD,BARWOOD,SANDALWOOD,orSANDERSWOOD, are chiefly used in wool dyeing, with other dye woods (such as Old Fustic, and logwood) for browns. They dye good but fugitive red with bichromate of potash, or alum.
Weld,Reseda luteola, is an annual plant growing in waste places. The whole plant is used for dyeing except the root. It is the best and fastest of the yellow natural dyes.
The plant is gathered in June and July, it is then carefully dried in the shade and tied up in bundles. When needed for dyeing it is broken into pieces or chopped finely, the roots being discarded, and a decoction is made by boiling it up in water for about 3/4 hour. It gives a bright yellow with alum and tartar as mordant. With chrome it yields an old gold shade; with tin it produces more orange coloured yellows; with copper and iron, olive shades. The quantity of weld used must be determined by the depth of colour required. Two per cent of stannous chloride added to the mordant gives brilliancy and fastness to the colour. Bright and fast orange yellows are got by mordanting with 8 per cent stannous chloride instead of alum. With 6 per cent copper sulphate and 8 per cent chalk, weld gives a good orange yellow. Wool mordanted with 4 per cent of ferrous sulphate and 10 per cent tartar and dyed in a separate bath with weld with 8 per cent chalk, takes a good olive yellow. 8 per cent of alum is often used for mordant for weld. A little chalk added to the dye bath makes the colour more intense; common salt makes the colour richer and deeper.
Weld is of greater antiquity than most, if not all, other natural yellow dyes. It is cultivated for dyeing in France, Germany and Italy. It is important as it dyes silk with a fast colour.
Mordant with 2 per cent chrome and dye with 60 per cent of weld in a separate bath. 3 per cent chalk adds to intensity of colour.
Mordant with alum, and dye with 1 lb. of weld for every pound of wool. Common salt deepens the colour. If alum is added to the dye bath, the colour becomes paler and more lively. Sulphate of iron inclines it to brown.
Mordant with alum with a little weld in the bath. Dye with weld. Add teaspoonful of tin to the dye bath. Boil in separate bath with 1/4 oz. madder or cochineal to the pound.
Fustic is the wood ofMorus tinctoria, a tree of Central America. It is used principally for wool. With Bichromate of Potash as mordant, Old Fustic gives old gold colour. With alum it gives yellow, inclining to lemon yellow. The brightest yellows are got from it by mordanting with tin. With copper sulphate it yields olive colours (4 to 5 per cent copper sulphate and 3 to 4 per cent tartar). With ferrous sulphate darker olives are obtained (8 per cent ferrous sulphate). For silk it does not produce as bright yellows as weld, but can be used for various shades of green and olive. Prolonged dyeing should always be avoided, as the yellows are apt to become brownish and dull.
Boil the wool with 3 to 4 per cent chrome for 1 to 1-1/2 hours. Wash, and dye in a separate bath for 1 to 1-1/2 hours at 100°C. with 20 to 80 per cent of old fustic.
Mordant with 3 per cent chrome, for 3/4 hour and wash. Dye with 24 per cent fustic and 4 per cent madder for 45 minutes.
Mordant wool with 8 per cent of stannous chloride for 1 to 1-1/2 hours, and 8 per cent of tartar. Wash, and dye with 20 to 40 per cent of fustic.
Mordant wool with 3 per cent chrome, for 3/4 hour and wash. Dye with 6 per cent fustic, 33 per cent logwood. Boil 3/4 hour.
Mordant with 25 per cent alum, wash after laying by for 2 days, dye with 5 to 6 oz. fustic to lb.
Turmeric is a powder obtained from the ground-up tubers ofCurcuma tinctoria, a plant found in India and other Eastern countries. It gives a brilliant orange yellow, but has little permanence. It is one of the substantive colours and does not need any mordant. Cotton has a strong attraction for it, and is simply dyed by working in a solution of Turmeric at 60°C. for about 1/2 hour. With silk and wool it gives a brighter colour if mordanted with alum or tin. Boiling should be avoided. It is used sometimes for deepening the colour of Fustic or Weld, but its use is not recommended, as although it gives very beautiful colours, it is a fugitive dye.
Quercitron is the inner bark of theQuercus Nigraor Q. tinctoria, a species of oak growing in the United States and Central America. It was first introduced into England by Bancroft in 1775 as a cheap substitute for weld. He says,
"The wool should be boiled for the space of 1 or 1-1/4 hours with one sixth or one eighth of its weight of alum; then, without being rinsed, it should be put into a dyeing vessel with clean water and also as many pounds of powdered bark (tied up in bag) as there were used of alum to prepare the wool, which is then to be turned in the boiling liquor until the colour appears to have taken sufficiently: and then about 1 lb. clean powdered chalk for every 100 lbs. of wool may be mixed with the dyeing liquor and the operation continued 8 or 10 minutes longer, when the yellow will have become both lighter and brighter by this addition of chalk."
"The wool should be boiled for the space of 1 or 1-1/4 hours with one sixth or one eighth of its weight of alum; then, without being rinsed, it should be put into a dyeing vessel with clean water and also as many pounds of powdered bark (tied up in bag) as there were used of alum to prepare the wool, which is then to be turned in the boiling liquor until the colour appears to have taken sufficiently: and then about 1 lb. clean powdered chalk for every 100 lbs. of wool may be mixed with the dyeing liquor and the operation continued 8 or 10 minutes longer, when the yellow will have become both lighter and brighter by this addition of chalk."
Flavin is extract of Quercitron bark, and is much used for bright yellow with tin.
Mordant with alum. Dye with 1 oz. Flavin.
Put into bath first 1/2 oz. Cream of Tartar. Then 3/4 oz. tin mixed with water (important to enter the Tartar first). Enter yarn and boil for 45 minutes. In the meantime have mixed up 1/2 oz. Flavin and 1/2 oz. to 3/4 oz. Cochineal (according to depth of orange required) with 1/4 oz. tin with a little warm water. Remove yarn, enter flavin, madder and tin, take off the boil, enter yarn and stir well. Boil 30 minutes.
The roots and bark ofBerberis Vulgarisis used principally for silk dyeing, without a mordant. The silk is worked at 50° to 60°C. in a solution of the dye wood slightly acidified with sulphuric, acetic or tartaric acid. For dark shades mordant with stannous chloride.
Genista Tinctoria.The plant grows on waste ground. It should be picked in June or July and dried. It can be used with an alum and tartar mordant and gives a good bright yellow. It is called greening weed and used to be much used for greening blue wool.
Ligustrum Vulgare.The leaves dye a good fast yellow with alum and tartar.
Most of the heathers make a yellow dye, but the one chiefly used is the Ling,Calluna vulgaris. The tips are gathered just before flowering. They are boiled in water for about half-an-hour. The wool, previously mordanted with alum or chrome according to the shade of yellow wanted, is put into the dye bath with the boiling liquor, which has been strained. It is then covered up closely and left till the morning. Or the wool can be boiled in the heather liquor till the desired colour is obtained.
Prepare by mordanting with alum. Take a sufficient quantity of onion skins and boil for 30 minutes. This gives a good yellow. The addition of tin will make the colour more orange.
Catechu (Cutch) is an old Indian dye for cotton. It can also be used for wool and silk, and gives a fine rich brown. It is obtained from the wood of various species of Areca, Acacia and Mimosa trees. Bombay Catechu is considered best for dyeing purposes.
Catechu is soluble in boiling water. It is largely used by the cotton dyer for brown, olive, drab, grey and black. (See pp.46,47,48.)
(For 6 lbs.) 1 oz. cutch, 1 oz. iron. Boil for 1/2 an hour in the cutch, then put into boiling iron, being very careful to stir well. Wash very thoroughly.
These proportions can be varied according to the shade of grey required; the more iron makes the colour browner, the more cutch the bluer grey.
The wool is boiled for 1 to 1-1/2 hours, with 10 to 20 per cent catechu, then sadden with 2 to 4 per cent of copper sulphate, ferrous sulphate, or chrome, at 100°C., in a separate bath for 1/2 hour.
The bark and twigs of alder are used for dyeing brown and black. For 1 lb. wool use 1 lb. alder bark. Boil the wool with it for 2 hours, when it should be a dull reddish brown. Add 1/2 oz. copper as for every pound of wool for black.
Sumach is the ground up leaves and twigs of theRhus corariagrowing in Southern Europe. It dyes wool a yellow and a yellow brown, but it is chiefly used in cotton dyeing.
The green shell of the walnut fruit and the root are used for dyeing brown. The husks to be used for dyeing must be collected green and fresh, then covered with water and kept from the light to prevent them oxidizing. In the walnut tree there is an astringent colourless substance which gives a greenish yellow dye. This has the property of absorbing oxygen from the air and turning dark brown. It is only the unoxidized pale greenish stuff that can act as the dye, the dark brown itself has no affinity for the wool. Acids should be added to the dye bath to prevent oxidization. Without a mordant the colour is quite fast, but if the wool is mordanted with alum a brighter and richer colour is got. When used they are boiled in water for 1/4 hour, then the wool is entered and boiled till the colour is obtained. Long boiling is not good as it makes the wool harsh. It is much used as a "saddening" agent; that is, for darkening other colours.
"The best and most enduring blacks were done with this simple dye stuff, the goods being first dyed in the indigo or woad vat till they were a very dark blue, and then browned into black by means of the walnut root."—William Morris.
"The best and most enduring blacks were done with this simple dye stuff, the goods being first dyed in the indigo or woad vat till they were a very dark blue, and then browned into black by means of the walnut root."—William Morris.
PEAT SOOT gives a good shade of brown to wool. Boil the wool for 1 to 2 hours with peat soot. Careful washing is required in several changes of water. It is used sometimes for producing a hazel colour, after the wool has been dyed with weld and madder.
OAK BARK. Mordant with alum and dye in a decoction of oak bark.
ONION SKINS. (Brown.) Mordant the wool with alum. Drying two or three times in between makes the colour more durable. Dry. Wash. Boil a quantity of onionskins, and cool; then put in wool and boil lightly for 1/2 an hour to 1 hour; then keep warm for a while. Wring out and wash.
BLACK. Mordant with 3% Bichromate of Potash for 45 minutes. Dye with 1 oz. Hematin crystals, 3/4 oz. madder, 1/2 oz. Persian berries. After boiling for 1 hour remove wool and add 1/4 oz. cream of tartar, 1 oz. cochineal, 3/4 oz. iron, 1/2 oz. copper sulphate. Return wool and boil again for 1/2 hour. Wash in soap.
MADDER for BROWN. (1 lb. wool.) Mordant with 1 oz. copperas and 1 oz. cream of tartar. Dye with 6 ozs. madder.
MADDER, etc., for FRENCH BROWN. Mordant with 3 per cent chrome. Dye with 8 per cent fustic, 2 per cent madder, 1 per cent cudbear, 2 per cent tartar. If not dark enough add 1 per cent logwood. Boil for 1/2 hour. Wash and dry.
TAN SHADE. (6-1/2 lbs. wool.) Mordant with 3 ozs. Chrome for 45 minutes and wash in cold water. Boil for 1/2 hour in a bag 5 oz. madder, 4 oz. Fustic, 1/2 oz. logwood. Enter the wool, raise to the boil, and boil for 45 minutes. By altering the proportions of madder and fustic various shades of brown can be got.
GREENISH BLACK. (For 1 lb.) Mordant with 3 per cent Chrome. Dye with 2 ozs. Fustic, 2 ozs. logwood, 1 oz. madder, and 1 oz. copperas.
DARK GREENISH-BROWN. (1 lb.) Mordant with 3 per cent chrome. Dye with 2 ozs. logwood, 4 ozs. madder, 1 oz. fustic, 1-1/2 ozs. copperas. Boil for 1 hour.
Green results from the mixing of blue and yellow in varying proportions according to the shade of colour required.
Every dyer has his particular yellow weed with which he greens his blue dyed stuff. But the best greens are undoubtedly got from weld and fustic.
The wool is first dyed in the blue vat; then washed and dried; then after mordanting, dyed in the yellow bath. This method is not arbitrary as some dyers consider a better green is got by dyeing it yellow before the blue. But the first method produces the fastest and brightest greens as the aluming after the blue vat clears the wool of the loose particles of indigo and seems to fix the colour.
If a bright yellow green is wanted, then mordant with alum after the indigo bath; if olive green, then mordant with chrome.
The wool can be dyed blue for green in three different ways:—1st in the Indigo vat, 2nd with Indigo Extract with Alum mordant, 3rd with logwood with Chrome mordant. For a good bright green, dye the wool a rather light blue, then wash and dry; Mordant with alum, green it with a good yellow dye, such as weld or fustic, varying the proportion of each according to the shade of green required. Heather tips, dyer's broom, dock roots, poplar leaves, saw wort are also good yellows for dyeing green. If Indigo Extract is used for the blue, fustic is the best yellow for greening, its colour is less affected by the sulphuric acid than other yellows.
According toBancroft, Quercitron is the yellow above all others for dyeing greens. He says:—"The most beautiful Saxon greens may be produced very cheaply and expeditiously by combining the lively yellow which results from Quercitron bark, murio sulphate of tin and alum, with theblue afforded by Indigo when dissolved in sulphuric acid, as for dyeing the Saxon Blue."
"For a full bodied green" he says "6 or 8 lbs. of powdered bark should be put into a dyeing vessel for every 100 lbs. wool, with a similar quantity of water: When it begins to boil, 6 lbs. murio-sulphate of tin should be added (with the usual precaution) and a few minutes afterwards 4 lbs. alum: these having boiled 5 or 6 minutes, cold water should be added, and then as much sulphate of Indigo as needed for the shade of green to be dyed, stirring thoroughly. The wool is then put into the liquor and stirred briskly for half an hour. It is best to keep the water just at the boiling point."
Dye the wool blue in the indigo vat, wash well. For 100 parts of wool put 3 of chalk and 10 or 12 of alum. Boil wool in this 1 hour. Then to same bath add 10 to 12 parts quercitron and continue boiling for 15 minutes, then add 1 part of chalk, this addition is repeated at intervals of 6 to 8 minutes till a fine green is brought out.
Mordant 1 lb. wool with 4 ozs. alum and 1/2 oz. cream of tartar. Dye blue with sufficiency of indigo extract, wash and dry. Prepare a dye bath with weld which has been previously chopped up and boiled. Enter wool and boil for half an hour or more.
Mordant with alum and cream of tartar, add to the mordanting bath a little weld or fustic. Dye with 6 ozs. fustic (or weld). Dye in a separate bath with indigo extract, a rather bluer green than is wanted. Then put into a yellow bath till the right shade of green is got.
For 1 lb. wool: 1-1/2 oz. alum, 1/2 oz. sulphuric acid, 1/2 oz. salt, 1/4 oz. Tin crystals. Dissolve tin in separate saucepan and mix half of it with 1/4 oz. Flavin, add both to the bath together with indigo extract (1/2 tablespoonful). When hot enter yarn and boil hard for 1 to 1-1/2 hours. It turns a green when exposed to air. Wash very thoroughly.
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 amount of the indigo extract to be used (according to shade of green required, 1/2 oz. indigo extract makes a good colour). Enter wool and stir rapidly for 5 minutes or so without boiling. Take out wool. Mix in the rest of the indigo extract. Enter wool and boil for 10 minutes. Take out wool. Throw away 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.
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 small dyer. It had its origin 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 with weld, flavin, turmeric (for which cotton has a strong attraction), and fustic. Great care is to be taken in dyeing yellow as it is not very fast to light. Greens may be got by dyeing in the indigo vat and then with a yellow recipe, purples from logwood with tin mordant, but purples and greens are unsatisfactory, and not suitable to the vegetable dyer.
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 may be used, but for light and bright colours a weak solution of carbonate of soda, 5%; or of caustic soda, 2%, should be used.
Alum.Alum (1/4 weight 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 well wash. Aluminium acetate solution as for silk (page56) may be used. After drying, the cotton may be passed through a fixing solution of some alkali, for examplessee page50. Before mordanting with alum, the cotton is often prepared with tannic acid.
Iron.Iron is usually employed as a "saddening" agent, i.e. the cotton after dyeing is steeped in a cold solution of the mordant. A further use is in dyeing black, 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 mordant for cotton but brightens 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 time in chrome solution, this oxidizes the colouring 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 for mordanting as it is the purest and is free from any other colouring matter; it is, therefore, used for pale and bright shades. But for dark shades, substances containing tannic acid are used, such assumach,myrobalans,valonia,divi-divi,oak galls,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 60°C. 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 acidequals4 lbs. sumach, 18 lbs. myrobalans, 14 lbs. divi-divi, 11 lbs. oak galls.
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.
Some recipes soak the cotton 24 hours, others 48.
Take 3 oz. well ground indigo, mix into a paste with hot water. Slake 3 oz. Quicklime and boil with 6 oz. Potash or Soda ash in sufficient water, let it settle, pour off the clear liquor in which dissolve the indigo paste, boil or keep hot 24 hours; it should then have the consistency of thick cream, with much froth. During the boiling, slake another 3 oz. quicklime, boil in a pint of water for 15 minutes, let settle, pour off the clear liquor in which dissolve 4 to 5 oz. green copperas. Add the indigo and copperas solutions to 5 gallons water, stir well, let vat rest, stir once or twice during 24 hours or until it appear ready for dyeing. Before use it should be stirred and let stand 2 hours. It should be a clear yellowish green with much scum.
The cotton to be dyed should be entered in dips of increasing lengths of time, as 1, 5, 10, 20 minutes, and aired in between, according to depth of shade required. It should then be well washed, passing through water slightly acidulated with Sulphuric acid (a teaspoonful to 1 gallon). When this vat appears exhausted and turns a dark colour it may be revived by adding 2 or 3 oz. Green Copperas dissolved as before. When again exhausted, more of all the ingredients must be added.
2 oz. Indigo, 4 oz. Copperas, 5 oz. Quicklime (fresh). Mix Indigo into a paste with hot water. Dissolve copperas inhot water. Slake lime. Fill earthenware jar with about 5 gallons cold water and add the Indigo, copperas and slaked lime in that order. Stir well, cover and let stand till next day or until vat is in proper condition; it should be clear brownish yellow with possible blue scum. There will be some sediment. The dyeing process is as in (1).
(For 1 lb. cotton.) The Turkey Red process is long and difficult. (1) Boil yarn 6 to 8 hours in a solution of carbonate of soda, 1-1/2 oz., wash well and dry. (2) Prepare a solution of 2 fluid ozs. Turkey Red oil, 2 ozs. ozrbonate of soda at 100°F., work cotton in this till thoroughly saturated, wring out, dry. (3) Repeat No. 2. (4) Repeat No. 2. (5) Steep 3 or 4 hours in solution of 1 oz. carbonate of soda at 100°F., wring out, dry. (6) Repeat No. 5 with a slight increase of soda. (7) as No. 6. (8) Steep 10 hours in water at 100°F., dry. The cotton should now be clear white. (9) Steep 4 hours in solution of 1-1/2 oz. tannic acid or 4 oz. Galls, at 100°F., wring out, dry. (10) Steep 24 hours in solution made by dissolving 10 oz. alum in hot water, and slowly adding 2-1/2 oz. carbonate of soda crystals, wring out and dry. The cotton is now grey coloured. (11) Dye with 2 lbs. madder. Bring slowly to the boil, boil for 1 hour, a white scum on the surface denotes the cotton has absorbed all its colour. A teaspoonful of chalk may be added to the dye-bath. The cotton is now dark claret colour. (12) To brighten, boil 3 or 4 hours in a solution of 1/2 oz. carbonate of soda crystals and 1/2 oz. soap. The bath should be covered, except for a small outlet for the steam which otherwise should be retained as much as possible. (13) The cotton can be further brightened by boiling with 1/2 oz. soap and a teaspoonful of Tin. Wash and dry.
(For 1 lb.) After boiling out in soda, wash and dry. Steep overnight in a hot bath of 1-1/2 oz. Tannic acid or 4 oz. Galls, dry, steep in cold solution of 1/4 lb. alum and 1/2 oz. chalk, dry, add 2 oz. more alum to solution and steep as before, wash and dry. Dry with 12 oz. Madder, bring to boil in 1 hour andboil a few minutes, rinse, re-dye as above, pass through warm soap bath, 2 oz., wash and dry.
(For 1 lb.) Mordant twice in Aluminium acetate, as described for silk (page 73), or in 1/4 lb. alum and 1-1/2 oz. chalk, steeping in cold solution. Pass through weak bath of chloride of lime, wash, dry. Dye with 2-1/2 lbs. weld and 1/2 oz. copper sulphate, boil for 1 hour, then boil with soap. Or dye with 2 to 3 oz. Quercitron, which should be brought slowly to the boil and boiled for a few minutes only.
(For 1 lb.) Steep overnight in hot bath of 1-1/2 oz. Tannic acid, or 4 oz. Galls, wring out, dry. Work 2 hours in bath of 1/4 lb. alum and 1/2 oz. chalk, dry, pass through weak bath of chloride of lime about 1 oz., dry. Return to alum bath and repeat process, wash well, dye slowly with 1-1/2 oz. Flavin.
(For 1 lb.) Boil 2 oz. Annatto with 1 oz. carbonate of soda crystals for 1/2 hour, then add to a bath containing a teaspoonful of Turkey Red Oil, boil for 10 minutes. Take off boil, enter yarn, boil for 1-1/4 hours, let cool to hand heat, remove yarn, wash slightly and dry quickly.
(For 1 lb.) Enter in one bath 1 oz. Cutch, in another 1/2 oz. Chrome. Enter cotton in cutch bath, boil 20 minutes, wring out, boil 10 minutes in chrome bath. Add 6 oz. fustic or 1 oz. flavin to cutch bath, re-enter cotton. Repeat above until the required depth of colour is reached, finish in cutch bath to obtain deepest shade, which may be darkened by adding 1 drachm or so copper sulphate. A greyish drab may be got by adding ferrous sulphate. All shades of brown may be obtained by decreasing or increasing the amount of cutch or by adding a little logwood or fustic, in which latter case the cotton should have been previously mordanted.
(For 1 lb.) Wash, steep overnight in hot solution of tannic acid, 1 oz., wring out without washing, work for 10 minutes in soda bath, at a temperature of 50° to 60°C., 1-1/4 oz. Wring out, work in cold solution of copperas, 1-1/4 oz., for 1/2 hour, return to soda bath for 1/4 hour. Wash, dye in bath of logwood 12 oz., madder 2-1/2 oz., and fustic 8 oz. Enter into cold bath and raise gradually to boiling, boil for 1/2 hour, pass through warm solution of chrome, 1 oz., wash, work through warm soap bath.
Greys may be obtained with 1 to 5 per cent of logwood after mordanting in a weak solution of iron.
The Zinc-lime Indigo Vat.It will be necessary to explain these words—Indigo blue is insoluble and cannot be used for dyeing. If however it is "reduced" or changed to indigo white, it has, while it is in this form, an affinity for vegetable and animal fibre. These fibres will take it up from the solution and retain it. If they are then exposed to the air, the oxygen acts upon the indigo in the fibre and turns it back again to indigo blue. Various chemicals can be used to reduce indigo blue to indigo white. I propose to describe how the work is done with zinc dust and lime as reducing agents.
In course of time the word "vat" has been transferred from the dyeing vessels themselves to their contents;i.e., the indigo dye liquor. By "vat," therefore, we understand not only the vessel used for dyeing indigo, but the solution of alkali salts of indigo white in water. This definition distinguishes theindigo vatcompletely from indigo extract, or any other improper purposes to which indigo may be put.
The zinc lime indigo vat is better than any other for dyeing cotton and linen. It is also very good for dyeing silk. It has many advantages over the hydrosulphite vat, as it is not nearly so much affected by changes of temperature and weather. It can be put to work after a six months' rest.
The disadvantage which it shares with the copperas vat, though in a less degree, is that there is a sediment whichmust not touch the stuff during the dyeing. This is avoided by hanging a net in the vat after the sediment has settled, or by dipping the skeins on rods.
It is essential that the indigo used should be of the best quality, and ground to so fine a powder that it will float on water. Coarsely ground indigo will never reduce and can be found at the bottom of the vat unchanged. It should be so fine that no roughness is felt with the tongue. Buy the best quality indigo ready ground, and if possible mixed to a paste with water. A 20% paste,i.e.20% of indigo and 80% of water, is a usual quantity. If indigo powder must be used it must be mixed to a paste very carefully, as it will, if properly ground, fly about like dust. The easiest method of mixing is to pour the required amount of boiling water into a jar (previously heated), then put in the indigo. Close the vessel tightly. The steam which rises will moisten the indigo so that it loses its tendency to fly about. After 10 or 15 minutes it can easily be mixed with a stick. The zinc dust should be dry and not caked.
The limeshould be in hard lumps. It should be bought from a reliable chemist in a sealed container, and kept sealed till wanted. If it is crumbling and cracking it has been exposed to damp air, and is partly slaked already, and therefore more or less useless.
As the indigo is more quickly reduced in a concentrated solution, a stock vat is first made and this is added to the dye vat as required. The vessel for the stock vat should have a well-fitting lid. A stoneware jar with a bung will do very well. To make a stock vat sufficient to furnish a dye vat containing 15-20 gallons use:—
10 oz. Indigo 20% paste (or 2-1/2 oz. indigo pasted with7-1/2 oz. of water),1-1/2 oz. zinc dust,4-5 oz. quick lime,4-5 pints of water.
Mix the zinc dust to a paste with a little of the water, gradually add the indigo and the rest of the water. The heat of the water should be not less than 160°F. as it will cool while thelime is being prepared. Slake the lime in a separate vessel by pouring about 5 oz. of water over it. When it begins to hiss and break, add more water little by little. When all the lumps have cracked up stir till a thick even cream is made. Add this to the other ingredients in the stock vat. Stir well. The stock vat should have a temperature of 120-140°F. It should be stirred at intervals. The vessel should be stood in hot water to keep the temperature as near 120°F. as possible. In about 5 hours the mixture has a pure yellow colour and is ready to add to the dye vat. (There is of course a blue-black scum of indigo on top.)
Preparation of the dye vat.The vessel used should be deep and upright so that an unnecessarily large surface is not exposed to the air, and a sufficient space for dyeing is obtained above the sediment. A galvanised dust bin, or a barrel (provided it is not of oak or any other wood which contains tannin), make good indigo vats. Put 16 gallons of water in the vat at a temperature of 65-70°F. In order to counteract the effects of the atmospheric oxygen contained in the water of the vat, additions of zinc dust and lime are made some hours before the stock solution is added. A pinch of zinc dust and an ounce of lime, previously slaked, should be added and the vat stirred. Stirring must always be done gently and smoothly, every effort being made not to take air into the vat. At the same time it must be stirred up from the bottom so that the sediment is mixed with the liquor above it. The best tool for this purpose is a broom stick, to one end of which a piece of wood is nailed, like a garden rake. When all is ready, carry the stock solution to the dye vat, and, to avoid splashing through the air, hold it in the water of the vat while gently pouring out half its contents. Stir up the vat and cover it until it shows a clear yellow colour under the surface of the scum. This may not happen for 24 hours. A good way to test the colour of the vat is to push back the scum with the edge of a saucer or plate, then dip it halfway into the liquor. Against its white surface the colour of the liquor will be plainly seen. It should look like good light ale. If the liquor is greenish and sufficient time has elapsed,another pinch of zinc dust and a little more lime must be added as before, and the vat again stirred, allowed to settle and again tested. A little difficulty may be found in getting the vat to start, but once it has worked well no difficulty will be found in starting it again. It will work more easily as it gets older.
As indigo does not penetrate easily, every effort must be made to help it to do so. The stuff to be dyed must be thoroughly scoured so that no particle of grease, size, or any other impurity is present. Every effort must be made to prevent unreduced indigo from attaching itself to the cotton. Never begin to dye in a vat which is greenish. The unreduced indigo will attach itself to the stuff and be wasted. Your time will also be wasted in washing it off.
The vat should be thoroughly stirred and allowed to settle each day before dyeing begins. When the sediment has settled, the froth should be carefully skimmed and kept to return to the vat when the day's dyeing is finished.
If a net is to be used it should be thoroughly wetted (if everything goes into the vat wet it will take less air with it). The net can be kept down by tying a few stones in a bag or an iron weight to the centre of it. If the hanks are to be dipped on a rod this may be of iron, or of wood suitably weighted. The hanks should not be less than 8 inches below the surface of the liquor and about 1 ft. above the bottom of the vat. The hanks should be turned after each dip, as, if the same end goes to the bottom each time it will be darker. A pulley over the vat to draw out the rod or net is convenient. The dyeings can then be allowed to drain a few seconds. Then wring each hank, shaking it out to get the air into it. After a sufficient airing, dip again. Many short dips with airing between will produce faster colours. Dip 1 minute, wring and air 2 minutes. Dip 2 minutes, wring and air 4 minutes. Dip 5 minutes, and so on.
As linen and cotton look so very much darker when wet than when dry, a bit should be dried to judge if the colour is right.
Indigo can be dyed from the palest sky blue to black. The very palest shade of sky blue is never very fast. The virtue which indigo alone seems to possess is that, though it may become lighter with continual use, it also becomes a clearer and more lovely blue. This is especially so on cotton and linen, for which it is a superb dye. The varying shades of indigo of butchers' coats, sailors' collars, and French porters' blouses always give us pleasure.