Prepare feathers by washing and rinsing thoroughly in hot water. Be
careful about rinsing to remove every particle of soap that may adhere
to the fibre, after which prepare bath as follows: One teaspoonful of
indigotine powder, diluted in one gallon of boiling water, and add
thereto about half a teaspoonful of oxalic acid, stirring around well
to thoroughly dissolve every particle of color. Enter feathers and
let them remain in bath about four minutes; after which take out and
rinse in luke warm water to remove the acid in feathers; next prepare
a bath of one gallon of hand warm water and add a small handful of
starch; add thereto a cupful of boiled logwood liquor and a few grains
of copperas, enter feathers, let remain in bath about three minutes;
take out and dry by rubbing between the hands in powdered starch, and
beat out on a clean board until all the starch has been removed. Should
you find your color darker than shade required, prepare a bath of half
a teaspoonful of oxalic acid in a gallon of hand warm water, and pass
feathers through about half a minute; take out and pass through boiling
water, after which pass through starch bath and dry. Should you find
shade too light, add more logwood to bath, increase temperature, let
remain in a couple of minutes longer and dry.