The Uni-ball Signo 307 is a unique addition to the Signo family! The ink in the Uni-ball Signo 307 iscontains cellulose nano fiber, the same tree pulp that paper is made from. This ingredient allows for a smooth and skip-free writing experience. This pen features a comfortable rubber grip and like other Signo pens, the ink iswater resistant, fraud resistant, fade resistant, acid free, and archival. UMN-307 0.7mm View All Uni-Ball Pens About Uni-ball: Uni-ball and Uni are subsidiaries of Mitsubishi Pencil Company. First founded in Tokyo in the late 1800s, they released their first ballpoint pen in 1959 and developed their first style of rollerball pen in 1979. Mitsubishis products include mechanical pencils, refills, markers, correction tapes, and their acclaimed gel and rollerball pens.