It depends on the tyer. Some stay together and some don't. What I do after receiving flies is go over the thread with head cement. Also some fish are hard on flies, Bluegills are one, Crappies OK. N/Pike always bite them off. Bass so-so. A flyfisherman never stops buying flies. I proably have easily 300-400. The expensive flies are the more tech/type used for salmon and steelhead or pike fishing and saltwater types, they can cost from 3-7 dollars a piece. These flies last longer than panfish flies.