while I usually will go with 100% cotton, not always! And as far as thread, I don't like the lintiness of cotton --to piece I usually go with C & C's poly/cotton blend or just found Superiors Sew Piece (??)--it's a poly #50 and really like it. On the long arm I use SoFine which is poly mostly, but will use a trilobal (poly) or Omni (poly) or sometimes either Superior's King Tut or YLI--though honestly once those are gone I won't be replacing--too thick for the heavy custom quilting I do and too linty. For Bat--Love,love,love washable wool--but usually use 80/20 Hobbs. If I plan to only use on the wall and plan to enter into local shows, I will go with a poly bat as it doesn't hold the wrinkles as tightly.