Acid-free ink that``s quick-drying, safe for archival documents and designed to be smear-free. Gel formula gracefully glides across paper. Rest assured each refill contains high-quality ink for consistent performance. Refill For Series: Hybrid® Gel, H2, Hybrid® Gel Grip Rtx/Dx, Clarius™ Gel Ink; Pen Refill Type: Roller Ball; Special Ink Type: Gel; Color(s): N\A.