Style 7500 is a 9.6 oz/sq yd boat and tooling type fiberglass cloth. 7500 uses the ECG 37 1/2 yarn in the warp and fill. The "G" filament used in 7500 being just 9 microns, versus the much larger cheaper-to-make 13 micron "K" filament used in style 1800 of the same weight and thread count, makes for a very flexible cloth. The majority of the 7500 we have is 38" wide and finished in the clear silane for any resin 627. All rolls but the 125 yard rolls will be rolled on 2" pvc, uness otherwise noted for factory short rolls.