Organic cotton batting is a heavier batting which is meant to be used as a foundation material in upholstery, not as a replacement for dacron/polyester, which is a lighter weight ‘finishing’ layer between the outer fabric and the layer beneath. The wool batting is the correct weight, and is used in place of the dacron/polyester layer.
In conventional upholstery, polyester batting is glued in place. In natural upholstery, instead of glue, the wool batting has a thin spun backing that can be stapled or stitched, depending on the upholstery application. Note: unbacked wool also sticks quite nicely to latex foam, and to burlap (a material often used on outside backs as a support layer for the lightweight ‘finish’ batting, and not in cushions). Wool batting does not require gluing.
Please note that wool batting DOES require an extra layer of ticking fabric between the outer fabric and the wool batting to prevent the wool fibers from migrating through to the fabric surface.