Our iron gall/ oak gall ink is made in our very own kitchen by our resident scribe and chemist. As part of our commitment to delivering to you only the very best historic scribal products we test every ink batch – not only on paper, but on our kitchen cabinets, floor, clothes, and hands. Thus we can assuredly assert to you that this ink is not only authentic and historic, but is also very permanent, and has a very nice flow. The ink in this listing is excellent for dip pens and quills, -is not suitable for fountain pens – it will eat the metal bits of your fountain pen if left in contact with the pen for a prolonged period of time. DO NOT INGEST.