Beyblade Burst String Launchers

Hey! So I have been inactive for many, many months. I haven't necessarily been out of beyblade but I wasn't paying attention to it. I am going to ask around and see if anyone knows if they know the material or where I could buy bulk of the string they use for launchers. I have learned inside and out for launcher and I am currently designing a way of how to replace string, and make it easily accessible to the public in my head of course and on paper. So please let me know if you know or just let me know your thoughts! I also did look for other threads and I could not find any. If you have questions, ask away!