The Pentel EnerGel Document is a rollerball liquid gel pen with pigmented, light-resistant black ink. The EnerGel Document ink has been certified ISO 27668-2 which is specifically intended for use on documents. The ink is both waterproof and smudge-proof (in outdoor conditions, the ink is weather resistant and will not bleed or become illegible even in drizzle or on damp paper.) The ink also has the important properties of being non-erasable and non-removable, and is also acid-resistant. This makes the pen the tool of choice for applications with specialised requirements, such as archive work. The original EnerGel ink gives contour sharpness, is fast drying and does not clog up or smear on paper. The elegant, black casing is fitted with a durable metal writing 0.7mm tip and also features a sturdy metal clip and an ergonomic rubberised grip for comfort. Made from 54% recycled materials, the environmentally friendly, pen is refillable and supplied in a cardboard wallet of 2.