Polar Black Bulletproof Ink - same as Eel Polar Black. All of the great qualities of Noodler's Standard Permanent Black plus freeze-resistant even in Scandinavia! The manufacturer also states that Polar Black has lubricating properties for all pistons and converters -- tested to flow smoothly in all types of feeders! Writes very smoothly in a rich dark black color. This listing is for a 3 oz. bottle of Noodler's ink in Polar Black. The product is new, current product directly from the manufacturer. The bottle is glass with a distinctive Noodler's Catfish label, and an outside Noodler's box. This ink is all U.S. made and boasts Archival, Anti-Forgery and Anti- Feathering features. The ink is specifically designed for fountain pen use.