like all cotton BUT here we don't easily get wide cotton for backing ,so sometimes have to use mix.
cotton for hand quilting BUT having just travelled 30 miles for matching american sulky have LOST it ,so unless it turns up will use gutterman poly.
IN ADDITION ,always used poly batting, but prefer warm/nat SO used it for last 5 BUT my stitches are not nearly so tiny/uniform as with poly [it seems to repel needle] SO next one will be poly.
MIX AND MATCH!!!!!!!!!!!!!!!!