These are monofilament fibers that are available in 3 different deniers (diameter of the fiber)- 7, 15, and 100. The fiber lengths are 1/4” (PVA7), 3/8” (PVA15), and 1/2” (PVA100). Due to the fine nature of these fibers, and the fact that they disperse into monofillament fibers, they are less likely to be visible in finished surface. How visible they are in relation to each other is in direct proportion to their various diameters (7 is least visible, 100 is most visible). Equally true, the small the fiber, the more fibers there are for any given unit of measure, the more likely they are to choke mixes at higher dosage rates. This is why the PVA100 are dosed at higher rates in the more flowable mixes than are the PVA15.