It is possible to write on Weatherproof Paper underwater with a standard ink pen (gas charged, write-anywhere pens even work upside-down-underwater.) iGage Weatherproof Paper is a synthetic film. The base film is porous and inherently has excellent ink absorption characteristics; the film is coated to optimize standard inkjet penetration and toner bonding. Ink and toner are tightly bonded to the sheet resulting in excellent pigmentation, color saturation and image definition.