Your warmest quilt would be wool batting (preferably old fashioned wool carded at the woolen mill), and tied. We make the ties loosely - don't pull the first knot tightly to keep the air in that area. If you've ever put insulation into a house, you know that you don't stuff in it. It needs to be kept loose to trap air. It's the air that is the insulation. The same happens to quilts. Machine quilted is not near as warm as tied because the layers are all smashed down and don't have any air in them.