A sealing strip on a release layer is disclosed. The release layer can include an envelope with walls cooperatively enclosing a pocket with an opening. The envelope can include a closure flap pivotable to close the envelope. A first location of the envelope can include a sealing strip releasably adhered to the envelope (or a release layer on the envelope). This sealing strip can be removable from the first location and placeable in a second location overlapping the closure flap in the closed position and an adjacent portion of an envelope wall. The sealing strip can include an adhesive capable of adhering to the closure flap and adjacent portion of the second wall for securing the closure flap in the closed position. The sealing strip can include a removable grasping tab connected by a weakened area. The sealing strip can be provided on a release layer independent of an envelope.