Iron Gall ink, Blue-Black writing fluid

For centuries this particular ink has been used as the standard writing ink for all types of documents. It was highly priced for its fade and water resistant qualities and is by far the best ink for parchment, producing writings which are completely permanent. The "modern"versions are for example Stephen's Blue Black writing ink and Arnold's writing fluid, which maybe used by your granddad. But unfortunately this ink is no longer produced and therefore I could digged up an old (german) recipe to produce the highest quality chancery iron gall ink, which is the legally compulsary ink to write state treaties and important documents, as for this ink the writings are very archival and writings will last for centuries without impairing the legibility of it (unfortunately my paper is cheap wood pulp based and contains acid, which will not last longer then a few decennia). The ink writes with a bluish hue and soon turns intensely black. The black writing is untouched by water and alcohol and cannot be removed from the paper by so-called ink killers (used to remove ordinary fountain pen washable inks). The ideal ink to sign important documents as cheques, treaties etc. The ink is so good that even rubbing alcohol cannot remove the writing from the paper, without destroying the paper itself. This ink is acidic and use in a fountain pen is rather risky, but one can sacrifice a cheap fountain pen as the ink may corrode the inner metal parts and can cause severe clogging. Flushing the pen every week is compulsory to prevent clogging. The safest way is to use a dip pen, like I showed on this video.