Actually, portrait and SD users can buy a 24" mat, then cut it down to the width of their regular mats. Line the cut edge with painter's tape, and you're good to go. I've also purchased Cricut 12x24 mats and modified them for my Silhouette SD using this method. Be sure to check the header on the lead edge too. It might also require some trimming if using Cameo or Cricut mats for an SD or Portrait machine.