Diamine brand ink has a long and rich history, dating back to 1864. Diamine ink is produced in the UK and is made with a gentle formula safe for all fountain pens. It has quickly become one of the most popular and sought-after brands around. A wide selection of ink colors is available. This special Registrar's Ink has long been used by registrars and clergy for filling out official documents due to its strong water and fade resistance. It is an iron gall ink, a very old form of ink made from iron salts and tannic acid. The ink is light blue when wet, but as it dries the iron in the ink quickly oxidizes and turns the ink to a dark blue-gray black.