I get newsprint end rolls at my local newspaper office. They are about 24" wide and have 15-20 (or more) yards of paper left on them. They're usually less than $1 a piece, but recently I went in on a Saturday morning and the girl at the counter said, "Oh, we don't charge for these on Saturdays!" I came out of there with as many as I could carry (6). They have to be cut up to whatever size I need, but I have an old rotary cutter I use for that. It might be a little tedious work, but hey, you can't beat that the paper was free!