NEW! Noodler’s Permanent Blue Ghost Invisible Ink. Safe for use in all Fountain Pens... When you want to write something no one else should see -- under normal light it’s invisible, under a black light visible... New 3 oz. bottle... This ink is new, current product directly from the manufacturer. The bottle is glass with a distinctive Noodler’s label, and an outside Noodler’s box. Ink is all U.S. made and boasts Archival, Anti-Forgery and Anti- Feathering features. The ink is specifically designed for fountain pen use.