4. (For 1 cwt., without previous blueing or ‘rooting,’)—a. Work the goods at about 200° Fahr. for 1 hour, in a bath made with 6 to 7 lbs. of cam-wood; lift, add 61⁄2 lbs. of copperas, and again work the goods for an hour, after which withdraw the fire, and allow them to steep for 10 or 12 hours; next drain and rinse them, and work them in a second bath made with 60 lbs. of logwood for 11⁄2 hour; lift, add 3 lbs. of copperas, and again work for an hour; lastly, rinse, air, and finish:—b. The goods are first worked, for about two hours, in a bath of 3 lbs. of fustic, in which 5 lbs. of bichromate of potash and 4 lbs. of alum have been dissolved; after exposure to the air for about an hour and thorough rinsing they are worked for a second two hours in a bath made with 45 lbs. of logwood, 31⁄2 lbs. of barwood or cam-wood, and 3 lbs. of fustic; they are then lifted, and 3 lbs. of copperas having been added to the bath, are again immersed and worked for half an hour to an hour.
5. (For 10 lbs. of wool or w. cloth.) Work the goods for 1⁄2 an hour in a bath of 1⁄2 lb. of cam-wood; lift, add 7 or 8 oz. of copperas, and after working them for 20 minutes, withdraw the fire, and leave them in the liquor for 10 or 12 hours; next rinse them in cold water, drain, and then work them for an hour in a bath made with 5 lbs. of logwood, to which 1 pint of urine has been added; lift, add 4 oz. of copperas, work them for half an hour longer, and, lastly, wash and dry them.
6. (For 7 lbs.) Take of galls (bruised), 1⁄4 lb.; logwood chips, 11⁄2 lb.; for the bath; boil or work the goods for 2 hours, take them out, add of copperas, 1⁄4 lb.; and when it is dissolved, work the goods through the liquor for at least 2 hours, keeping the bath nearly boiling; again take them out, wash, and air; then add 1 oz. more of copperas to the bath, and pass the cloth through it for another hour; lastly, air, rinse, and finish.
7. (For 5 lbs.) For the first bath—bichromate
of potash, 8 oz.; alum, 6 oz.; fustic, 4 oz.; for the second bath—logwood, 4 lbs.; barwood and fustic, of each 4 oz.; to which add, after the lift, copperas, 4 oz.; the process being conducted as in 4, b. This, as well as the two formulæ immediately preceding it, is particularly suited to articles of dress dyed in the small way, at home. When the articles are only re-dipped, as it is called, a proportionately smaller quantity of the ingredients may be taken.
Concluding Remarks. In dyeing black, particularly on wool, it is absolutely necessary to take the goods out of the dye-bath several times, and to expose them to the air. This is called “airing” them, and is done to allow the oxygen of the atmosphere to act upon the ingredients of the dye, and especially on the iron; as without this action of the air a good colour cannot be produced. The usual proportions employed by the dyers of England are 5 lbs. each of galls and copperas and 30 lbs. of logwood for every cwt. of cloth; but these weights are frequently increased for choice goods, just as they are always lessened for common ones. The other astringent substances used as substitutes for galls in dyeing black are taken in quantities proportionate to their respective strengths, that of good Aleppo gall-nuts being referred to as a standard.
The German wool-dyers usually commence their process with a mordant of Salzburg vitriol (3 parts) and argol (1 part); and after exposure of the goods in a cool place for 24 hours, work them in a bath of logwood (5 to 6 p.) and fustic (2 p.); after which the bath is restored by the addition of verdigris (1⁄4 p.) dissolved in vinegar and the goods again worked through it for about 1⁄2 an hour. This is for 20 parts weight of wool or cloth.
Black marinos are usually mordanted (hot) with about 1⁄10th of their weight of copperas, and then aired for 24 hours; after which they are dyed in a boiling bath made with about 1⁄2 their weight of logwood with the addition of about 2% of argol or tartar.
As black is the shade most commonly attempted by amateur dyers, it may be here necessary to call their attention to what is said on mixed fabrics in our article on DYEING; since an inattention to this point will inevitably cause the failure of their efforts.
According to Muspratt, a mixed fabric of silk and woollen may be dyed black by one process, as follows:—Work the goods an hour in a solution of 8 oz. each of tartar and copperas, and wash out; work for 15 minutes in a decoction of 4 lbs. of logwood; lift, add 1 oz. of bichromate of potash, work for 1⁄2 an hour, and dry. And a mixed fabric of cotton, silk, and woollen:—Steep for six hours in a bath made of 2 lbs. of sumach; then work for an hour in a solution of 6 oz. each of tartar, sulphate of copper, and copperas; wash, and work 1⁄2 an hour in a decoction of 4 lbs. of logwood; lift, add to the bath 1 oz. of copperas; work ten minutes, wash, and dry. If a very deep black be required, 1 lb. of bark is to be added with the logwood. See Dyeing, Mordants, &c.