For machine quilting I will generally use a poly batting. It is easy to work with and is full. If I am hand quilting I want to use Warm and Natural as it is easy to pass a needle through and is a nice warm quilt when it is finished. Now if I am doing hand Trapunto and I want that 'fluff' I will again use a poly batting. If I am making a quilt for someone other than family (which I am being paid to make) that person chooses the batting.