COFFEE BROWN.
Have the feathers will cleaned and rinsed, bleaching being not required, prepare a bath with three per cent. alum (of the weight of feathers), at 170° F., add indigo carmine, bordeaux and azo yellow, according to sample, and dye to shade while slowly raising the temperature to near the boiling point, but bring not to boil, but continue until the indigo carmine is well up. A less fast color is obtained with archil, indigo carmine and picric acid. When finished dyeing, rinse, starch and dry as usual.
The dyestuffs for brown being nearly the same for all shades, while the depth and tone of the color is produced by differently proportioning the quantities of the different dyestuffs and the time of dyeing, it is advantageous to have the solutions of dyestuffs near by on hand; it is advisable, however, if good work is intended, to always filter before using solutions which have been standing for some time. This precaution is necessary, because from most solutions, if allowed to stand for a day or longer, some dyestuff which was not dissolved but only suspended in the liquid, separates out forming a more or less copious sediment which, if it passes into the dye bath, settles upon the feathers causing spots or streaks of a different shade than the rest of the feathers.