Corrugated Cardboard Mailing Boxes Available In Over 200 Sizes!Corrugated mailer boxes are perfect for mailing anything from small, fragile items to books, pictures, literature, and garment. These crush-resistant die-cut mailers are all one piece and fold together in seconds. They are specially manufactured mailing boxes that fold up and lock themselves closed without tape to seal shut. These cardboard mailers are manufactured from 32 ECT lightweight B flute corrugated material and have white outer and brown inner surfaces (unless otherwise noted). With over 200 sizes of corrugated mailers, we're sure to have a size that will suit your needs.