DYEING DIRECTIONS
For cotton and linen, measure out the color and dissolve it in hot water to which has been added twice its amount of sodium sulphide (crystals) and a quarter or third the amount of soda ash. (In all these formulæ washing soda may be used in place of soda ash—only in quantities almost twice as large.) It is advisable, though not absolutely necessary, to add also to the dye-bath one or two tablespoonfuls of Turkey red oil—a kind of liquid soap made by treating castor oil first with sulphuric acid and then with soda. This prevents the formation of a dark scum on the surface of the dye-liquor, which is likely to cause streaks in the finished goods, hard to wash out.
Into the dye-liquor immerse the well-wetted goods, and heat them, turning them constantly, and keeping them as far as possible away from the air and under the level of the liquid. Just before the boiling point is reached take out the goods, and add salt in the proportion of, say, two spoonfuls of salt for every teaspoonful of dyestuff used. Stir till the salt is all dissolved, put the goods back, and continue to turn them as before, keeping the goods down under the liquor and not allowing it to boil.
After dyeing just below the boiling point for fifteen minutes, remove the heat, take out the goods, and—as quickly as possible—run them carefully backward and forward through the wringer (changing the folds of the goods each time) until the excess of dye liquor is entirely squeezed out. Then shake them out, hang them up for fifteen or twenty minutes in the air to oxidize and “set,” and after this wash them thoroughly in a bath of boiling soapsuds until all the loose color has been removed. Finally, rinse them free from soap, and hang up to dry.
When light shades are desired, or when the goods are tender, the dyeing can be done at lukewarm temperature, and without the addition of salt, with no detriment to the fastness of the color. In this case, however, much of the dyestuff will be wasted in the unexhausted dye-liquor.
List of Selected Dyestuffs.—
| Badische— | Kyrogene Brown, R R O |
| Kyrogene Yellow, G G, extra | |
| Kyrogene Direct Blue, 3 B, extra | |
| Kyrogene Black, T G O | |
| Cassella— | Immedial Bordeaux, G |
| Immedial Yellow Olive, 5 G | |
| Immedial Direct Blue, B | |
| Elberfeld— | Katigen Yellow, G F, extra |
| Katigen Indigo, C L G, extra | |
| Katigen Deep Black, B | |
| Kalle— | Thio Indigo Red, B |
| Thion Yellow, 3 G, extra | |
| Thion Blue, B, conc. | |
| Thion Black, G, conc. | |
| Metz— | Thiogene Brown, G R |
| Thiogene Gold Yellow, A | |
| Thiogene Green, G | |
| Thiogene Cyanine, G | |
| Thiogene Black, M A, extra strong |
These Sulphur colors are particularly strong in various shades of black, blue, and brown. Some of the yellow shades, also, are very fast and good. The class is deficient, however, in reds—the only one so far discovered being Thio Indigo Red B (Kalle), which really belongs to the Indigo or Vat colors, described in the next chapter, and which does not give very powerful shades when used as a Sulphur color. As a rule, these dyes produce shades that are softer, deeper, and much less brilliant than those of the Direct Cotton or Salt colors. Being usually mixed, and not simple primary, colors, they are not very easy to dye to shade, especially as the color of the freshly dyed goods changes considerably while it is being oxidized. On the other hand, they give, without mixing, extremely pleasant tones, and are all very fast to washing and, at any rate as regards the selected colors, are fast to light.
When exposed to strong direct sunlight some even of the best of them are liable to change their shade somewhat; but even then they will be found to fade to nice, soft shades not out of harmony with the original. When very great fastness to light is necessary, it may be worth while to after-treat them as described in Chapter III, by keeping the dyed goods for twenty or thirty minutes in a hot bath (not boiling) containing small amounts of copper sulphate, bichromate of potash, and acetic acid.