I think it's really cool that Expo is starting to produce that marker that has the little felt eraser on the other end. Very handy.
Keep up with more of the Lovakhiin's antics over at ROFLrazzi!
Maybe it's Sharpie.
I'm pretty sure Crayola has a special package just for these. Specialized felt tips and whatnot.
Making cancer look awesome one sharpie at a time!
I don't think Slipknot makes white merchandise.