Easy Fold Mailers or variable depth folders or book folders are a great way to ship books, photo albums, small picture frames, catalogs, etc. These one-piece corrugated folders have bending lines at multiple depths to ensure a custom fit for your products. These types of corrugated folders are used by numerous ecommerce companies to optimize packaging inventory and lower CFT costs associated with regular packing boxes. Quick assembly and requires no glue, tape, or stapling. Made from high grade Kraft paper with 25 ECT value.. Shipped and stored flat. You can find various sizes of easy fold mailers to suit a wide range of products. These corrugated folders online are available in white or brown colours.