old post this one,unger micro good for dry days but get damp quikly,used to get scrim from textile mills locally cut and hemmed to size for next to nothing,i like the loosely woven ones ,grade 2 or b is that not how scrim should be so you can scoop the water up?.grade a ones just dont work as well.grade b works best imo,need an old timer to keep us right.wont use grade a wasted my money.