The standard in Europe for more than 1,400 years, declining only in the 20th century, iron gall ink is a true solution with no solid residue suspended in the bottle. The resulting color in KWZ’s modern formula is very bright when wet on the paper, deepening and intensifying as it dries. The inks demonstrate lightfastness and high water resistance. That is, in the event of wetting, the iron gall component remains intact even if the topmost portion of the dye washes away, leaving the text fully legible.

Iron gall ink is compatible with dip and fountain pens, though fountain pen users should take extra care and only pair this ink with pens they use frequently. Additionally, proper cleaning and maintenance can help prevent corrosion within the instrument.