BARBERRY. The roots and bark of Berberis Vulgaris, 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.
DYERS BROOM. Genista tinctoria. The plant grows on waste ground. It should be picked in June or July & 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.
PRIVET LEAVES, Ligustrum vulgare, dye a good fast yellow with alum and tartar.
HEATHER. 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, is put into the dye bath with the 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.
Recipes:—1). Yellow for Wool. For 6¼ lbs. mordant with 5 oz. alum for 1 hour and wash. Boil up 8 oz. heather twigs, leaves and flowers. Enter the wool and boil for 1 hour. Wash in cold water & dry.
2). Golden Yellow for Wool. For 6¼ lbs. mordant with 3 oz. bichromate of potash for ¾ hour. Wash in cold water. Dye with 50 oz. heather and boil for 45 minutes.
CHAPTER IX.
BROWN AND BLACK.
CATECHU. ALDER BARK. SUMACH.
WALNUT. PEAT SOOT. LOGWOOD,
AND OTHER DYES
CATECHU.
Catechu, (Cutch) is an old Indian dye for cotton. It can be used for wool, 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 the 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. The ordinary method of dyeing cutch brown on cotton is to steep the cotton in a hot solution of catechu, containing a small addition of copper sulphate, and leave it in the solution for several hours. To 7 or 8 gallons of water put 1 lb. catechu and boil till all is dissolved, then add 1 to 2 ozs. of sulphate of copper and stir. It is then put into a boiling chrome bath (3%) for ½ hour. For deep shades the dyeing and chroming operations are repeated. With alum mordanted cotton, the colour is a yellowish brown, with tin it becomes still yellower. With iron it is brownish or greenish grey. When catechu only is used, a darker shade of brown is got by adding to the catechu 6% of its weight of copper sulphate. When mordants are used, they may be applied before or after the chrome bath, the cotton being worked in their cold solution.