Super-smooth gel ink. Permanent. Acid-free. Comfort Zone grip. Acid-free scrapbook safe. The quality-crafted, ultra-expressive gel ink pen. Writes medium lines with smooth gel ink. Latex-free rubber Comfort Zone grip for added writing comfort and control. Acid-free formula won't affect pH level of paper. Sign checks, wills and contracts with peace of mind. Permanent, acid-free ink is ideal for scrapbooks, journals and keepsakes. Refillable - uses KF8 refill cartridge.