Grafix Duo-Shade is a special paper used to create many of the original Mirage Studios Ninja Turtles comics. One of the old Mirage artists, the great Jim Lawson, recently gave me a couple of the remaining sheets of their very limited reserves. Production of the paper was discontinued in 2009. Basically, it had hidden cross-hatched lines in it that could be brought out by special chemicals which you could apply with a brush. I shot a couple videos of it in action for posterity.
Here’s a Ninja Turtles page drawn using the paper. (via)