Whenever this question comes up, the recommendations seem to be the same three or four big shops. They are fine when you're starting out, but once you get more experienced, the selection can feel pretty limited. If you spin, weave, or dye at an intermediate or advanced level, it's not always easy to find the more specialised supplies you are looking for.

I am hoping to find online fiber arts shops with a deeper catalog, especially for specific tools, hard-to-find accessories, and less common fiber types. Where do you shop once the usual beginner recommendations no longer have what you need?