The title explains it self.
50% poly 50% nylon?
O.o
Fabrics/Sewing store? Jo-Anns?
Wal-Mart?
Edit:
…LOL
Thought you were looking for thread to make string.
Chaos 422. This is my review: Chaos 422 String Review - Yo-Yo Reviews - YoYoExpert
Chaos 422, I make some, and so may many other homemade string-vendors, if you ask them.