Diamine Beau Blue Fountain Pen Ink 30ml. This premium ink is suitable for all brands of modern and vintage fountain pens. Manufacturers since 1864, Diamine Inks relocated to this purpose built ‘state of the art’ factory in Liverpool in 1925, where they successfully carried on using the traditional methods and formulas for ink production. Over the years the company has changed hands and are now located close to the world famous Aintree Race Course.