EnerGel 0.5 mm Permanent Retractable Rollerball Pen - Black (Pack of 12) Permanent, waterproof, lightfast ink Ideal for signatures, contracts, witness statements and all important documents Archive-safe - certified to DIN ISO 27668-2:1999 Quick drying ink reduces smudging on hands or paper 0.5mm tip delivers approx. 0.25mm fine line width