Xerox has invented a new type of paper that fades after 16 to 24 hours, allowing the paper to be reused. They developed compounds that change color when they absorb a certain wavelength of light but then gradually disappear. It's perfect for stuff that only needs short viewing, like emails or web printouts or any other crap you don't need to look at for more than 5 minutes. You know or porn. Gotta erase the evidence somehow.