Here's another neophyte quiz for you guys. This time the topic is tying thread. I've noticed that thread comes in different sizes, brands, and materials. I get the size thing. That makes sense to me so far. What about brands. What really is the difference between say Danville and Uni-thread? Will a tier eventually need or want both? Why? How about materials? Other than personal preferance, is there any real reason for the different thread materials?