Subsidiary Material Selecting and Qualified Sewing Craft- Everything from the dyes and fabrics to accessories like sewing thread and zippers are tested and verified for long-lasting and highest safety standards. Zipper Closure And Concealed Corner Ties- The four corner tie hooks ensure that your comforter quality remains immovable in the cover to ensure the duvet is non-slip, and zip the cover closed for a fashionable bed set.