The Zig Writer is a double-ended marker that features a .5mm fine tip on one end, and a 1.2mm round bullet tip on the other- making it a great choice for writing, "dot" lettering, or coloring books! The water-based pigment ink will not bleed through your papers! Ink is also photo safe, acid-free, archival quality, light-fast, waterproof, non-bleeding, Xylene-free, and odorless.