You can get a good substitute for polypropylene at the craft store in the form of "macram?" cord. $10 will buy you more of one color than you would ever use unless you are a commercial tier. The only down side is that you have to untwist the weave and it will have some kinks in it until it gets a chance to relax. PM your address and I'll send you some yellow and white to try out. It is great for posts and under wings. It can also be used as a substitute for calf body hair.