Kit for making your own ink:
90gr Galla pulvis (ground galls), 30gr FeSO4, 10gr Gum Arabic
Making your own ink is easy:
boil 0,4l of water, then add the Galla pulvis and the Gum arabic. Stir well and add the iron salt.
Leave the ink in an open pot to ripen for about 4 weeks at a warm place.
Not for fountain pens!