Roptex® (Brown Kraft) Open End Catalog with Multi-Tak™ Open End Catalogs have their flap on the short dimension. These envelopes are manufactured using durable, SFI Certified Brown Kraft paper with center seam construction and a Multi-Tak seal. Multi-Tak is a mulitiple use closure with self-sealing adhesive applied on back of envelope with a poly film on flap - sealing when joined but allowing easy separation for re-use.Brown Kraft (SFI CERTIFIED) Vellum FinishCenter Seam No Window Multi-Tak Seal Flap Down