For the modes it is impossible to give generally applicable directions,
as these colors are of an indefinitely varying character, consisting in
modifications of other compound or mixed colors which are affected by
sometimes very trifling, unmeasureable additions of a toning dyestuff,
and coloring effects are produced which cannot be described nor defined
by names, but must be judged by the experienced eye of the dyer. Most
of these colors are derived from grays or browns as above remarked,
and the safest way for the dyer is, to begin dyeing with light shades
of the prevalent characteristic color and give them the peculiar tone
by the addition of other colors by drops. The proportions of dyestuffs
thus ascertained for light shades, are then easy to increase for deeper
shades. It needs not to be remarked, that for these colors the feathers
must be bleached, especially for light and medium shades, and that,
if unbleached, grays are to be dyed in dark shades, the effect of the
natural color must be considered in composing the dye.
In general all modes are dyed upon a bath which is acidulated with
bisulphate of soda, with azo orange, azo yellow, azo brown, acid
violet, indigo carmine, solid blue or cloth blue, induline or
nigrosine, archil or acid fuchsine. For brown modes, solution of
Bismarck brown may be added at the beginning, in which case the other
dyestuffs serve only for giving the peculiar tone.
For a yellowish green mode take orange O, azo yellow, and solid blue
(fast blue); for darker shades add a little violet 6 B., or a few drops
sulphate of indigo. If alizarine dyestuffs are to be employed, use
tartaric acid as mordant, but for neutral dyestuffs add also a little
alum to the dyebath.
For gray modes use the same dyestuffs as above, excepting the orange,
instead of which a blue-red dyestuff is to be employed, such as azo
rubine, bordeaux, fuchsine, etc., with the addition of a little acid
green. The bath must be acidulated with a little sulphuric acid, or
better with tartaric acid, or tartaric acid and alum, and after dyeing
the feathers must be rinsed, starched and dried as usual.
For particularly fast modes add only tartaric acid to the dyebath and
no alum, and a few drops of solution of thio-scarlet, thio-rubine,
and thio-brown; for grays add a little azo yellow and sadden with
solid blue. Alum does not agree with the thio dyestuffs which are
manufactured by Dahl & Co., Barmin, and are fast against soap and
light. Feathers dyed with these dyestuffs which have become soiled, can
be washed, therefore, with neutral soap without injury to the color,
but must naturally be dressed anew.