We all have seen one of those trucks on the road hauling pieces of glass for windshields or what ever. The contents to be delivered locally. The glass is packed in various items to prevent breakage. One outfit here gets little pieces of hard foam of different sizes that they throw away. I find that these pieces can be useful to the tyier . Perhaps you might. here's a picture.Flies are a size 10. Piece is 2 by 3 by 1/2 inches. I don't know if I can get any more but maybe you can.