I have a roll of 36" very heavy paper we purchased at Home Depot mounted on the back of my 36" Belmont Loom. When I tuck it in the warp, it winds on nice and straight. As I advance the warp I wind it back on the roll. I pulled 20 yard off the roll, wound it tight and cut off 4" with a band saw (used to use an electric knife) to make a similar set-up for my 32" Belmont. Both rolls are marked at every yard so I have a good idea how much I have left to weave.
I found several 20 yd rolls of 48" industrial vinyl wallpaper (without paste) at a junk shop for $10/roll, that has been used for over 15 years where I taught weaving. We also shopped stores like the home depot for clearance wood slat blinds. Woven beach mats are also good separators.
Years ago, at Convergence in Toronto in a weaving tips seminar, a weaver made an apron by folding a 15 yard piece of heavy muslin in half. She wound it on her back beam putting in 4 sticks on the first lap and 1 stick in different places on each of the other laps, marking the placement of each stick as she went. Once it was all wound on and marked, she unrolled it and sewed the muslin to create pockets for the sticks. A box sat under her back beam to collect the apron as the warp advanced. I thought it was a pretty slick idea.
