Artist Daniel Eatock 
In 2008 U.K. based artist/designer Daniel Eatock did an interesting experiment with markers and paper. Using upside-down drinking glasses arranged in tight rows he stood individual markers on end allowing the ink to fully drain and soak into the stack of paper. The description from his website:
Over the course of the 39 days of the exhibition (September 18 through October 26, 2008), the paper absorbed the ink from the pens. The sheets at the top of each stack absorbed more ink than the sheets farther away from the tips of the pens. The result is an edition of organically related prints, each unique.
Check his website for images of the project and the unique print editions.
