"Instructions to make ink. Take one pound of copperas and one pound of galls. Break the galls and soak in three cuartillos [c. 3.5 l] of water for three days. Boil until three quarters of the water is gone and strain. Add one ounce of gum and mix until the gum melts. After the water has cooled down add one ounce of copperas, mix and let it rest for a day. Strain and pour into the vial."