Flexible Sizing: These bookfolds are perforated at multiple depths, allowing you to adjust the size based on your needs. You can fold them to close at either 1/2" or 1" or 1 1/2" or 2". Easy Folding: The perforations make folding a breeze. Simply place your product in the center, fold in the sides, and seal. No complex carton setup required! Sturdy Material: These bookfolds are manufactured from heavy-duty ECT-32-B flute corrugated. This ensures durability and protection for your items during transit. Multiple Uses: They are great for books, catalogs, framed pictures, and other items. Whether you’re sending out promotional materials or protecting valuable prints, these bookfolds have you covered Space-Saving: They come and store flat, saving storage space until you’re ready to use them. In summary, 12 1/8" x 9 1/8" bookfolds provide flexibility, ease of use, and reliable protection for your items. Whether you’re a business or an individual, these mailers are a practical choice!