Ok, I just remembered something... Rough Paper! ha ha ha... while studying in Jamnagar, some newspaper company used to sell unusable paper as rough paper to students for rough/revision work. Darn! Even I bought it once. I remember there used to be students who'd use up bundles and bundles of those rough paper sheets. And each bundle had rough paper roughly 4 times the size of a single bed sheet. And one can use it on bot the sides ofcourse. Whoa... i used to feel too dumb to not use such vast amounts of revision paper. Man, that was one loser feeling i tell ya.
Something like this, only three times bigger and one sigle folded sheet!

http://www1.istockphoto.com/file_thumbview_approve/2596849/2/istockphoto_2596849-blank-newspaper.jpg