If you hang only very large quilts - aka king size - with extra-heavy backing, like Fireside or Cuddle, then you may need a few extra magnets, in addition to what's provided in the initial Quik Hang Magnetic Quilt Hanging System package to do the job. 

This add-on SewTites Quik-Ease Magnet 5-pack to make hanging your quilts even more of a breeze! 

Each SewTites Quik-Ease magnet measures 3.98” x .59” (101 x 15 mm).