(For 2½ lbs. wool). Mordant with Bichromate of Potash, 1½ oz. in 10 gallons of water. Dye with 6 to 8 oz. cochineal. With alum mordant (4 oz.) a crimson colour is got. With tin mordant (2 oz.) a scarlet. With iron mordant (2 oz.) a purplish slate or lilac.
10). Scarlet, for Wool.
Mordant the wool for 1 to 1½ hours with 6% stannous chloride and 4% cream of tartar. Wash. Dye with 5 to 12% of ground cochineal for 1 to 1¼ hours. To dye the wool evenly, enter it in both the mordant and the dye when the water is warm, and raise gradually to boiling.
11). Scarlet, for Wool.
Fill the dye bath half full of water, add 6 to 8% of Oxalic acid, 6% of stannous chloride and 5 to 12 per cent. ground cochineal, boil up for 5 to 10 minutes, then fill up the dye bath with cold water. Introduce the wool, heat up the bath to the boiling point in the course of ¾ to 1 hour and boil ½ hour. Washing between mordanting and dyeing is not absolutely essential. The addition of tartar up to 8 per cent. increases the intensity and yellowness of the colour.
In order to obtain bright yellow shades of scarlet it is usual to add a small proportion of some yellow dye to the bath.
Wool mordanted with 10 per cent. of Copper sulphate and dyed in a separate bath with cochineal gives a reddish purple, or claret colour.
With ferrous sulphate as mordant very good purplish slate or lilac colours can be got. Mordant and dye in separate baths. Use 8 per cent. of ferrous sulphate and 20 per cent. of tartar.
12). Crimson for Silk.
Mordant the silk by working for ½ hour in a concentrated solution of alum, then leave to steep over night. Wash well and dye in a fresh bath containing 40 per cent. of cochineal. Enter the silk at a low temperature and heat gradually to boiling.