20 x 20 x 6" Kraft Jumbo Mailers. Jumbo mailers in hard-to-find sizes. Great for shipping framed posters or artwork. These one-piece mailers have scores at multiple depths to ensure the proper fit for your products with 1-6" depths. Simply place product in the center, fold in the sides at your desired depth and seal with tape. Economical 200#/ECT-32-C kraft corrugated construction.