An 18-section foldout with 143 dyed feathers and a dyeing instruction sample book.

Dye feathers by boiling them with 2-8% sulphuric acid and 10-20% Glauber’s salt crystals, depending on the desired shade depth. Repeat the dyeing process until the bath is exhausted and the shades are level. Boil the feathers for approximately one hour.

Thoroughly rinse, dry, and steam (if needed).

Thoroughly clean the feathers prior to dyeing. Use a diluted, lukewarm solution of olive oil soap with a hint of ammonia. Tetrapol can also be included in the solution. After cleaning, rinse the feathers well and follow the aforementioned instructions.

h/t: vintag.es