I obtained some old fly tying materials including a variety of thread. The paper tags on the ends of a lot of the spools are missing so I don't know the weight of the thread for some of them. Some seem a little dusty. My main concern is that some of the thread breaks pretty easily if you pull on it. I have tried comparing it to some other 3/0 and 6/0 thread that I have and is seems to break easier then it does. Can thread go bad if it is old? Can it loose it strength, or could this be thinner 8/0 thread.