I have not been pleased with the commercially available chopped fiberglass. I stays too rigid (like mixing in uncooked long grain rice) and does not smoothly conform to the surface it is being applied to. (See pic. #1) That makes it nearly impossible to get the cloth to lie down and conform to the mold surface adequately. In turn, this weakens the strenth of the layup, which is counter tothe point of adding it in the first place.

Therefore I take the really small pieces of my scrap FG cloth and put it in a small Tupperware container. I then stick the tips of sharp scissors inside the container and cut repeatedly. I want thecloth to be mainly in individualstrands, but don't overdo it or you won't havemuch strength being added(usuallyaboutthe time myhand starts getting tired, anyway). In my opinion this is a filler material that adds at least a little bit of strength, as opposed to microballoons, and also helps to hide the weave ofthe cloth being applied. Andby using the scrap, it is essentially free (I was going to throw it away, anyway), while working better for my needs than the commercially available option.