registrar's blue black

Diamine Registrar's Blue Black is an iron-gall ink known for its deep blue that darkens to a rich navy or blue-black upon drying, offering medium shading and exceptional high water resistance. It's praised for its archival permanence and dry flow, making it ideal for professional or formal writing where documents must withstand time and moisture. This ink suits fountain pen enthusiasts seeking a reliable, dark blue-black without sheen or feathering.