10 yard rolls of style 7781, 8.95 oz/sq yd 8 harness satin weave fiberglass cloth with blue tracers. This cloth has blue tracers in the fill direction, or side to side, every 8". The blue tracer is one singe strand of fill yarn that provides a reference for the discriminating composite builder to use in better
positioning the fiber orientation of the glass fibers. This is commonly used by helmet manufacturers, like motorcycle and goalie helmets, who put multiple layers at alternating orientations.