Closing, sealing, and reinforcing are primary considerations in preparing the
outside of a parcel for mailing. The main materials for closing, sealing, and
reinforcing mailing containers are adhesives, bandings (strappings), staples
and steel stitching, and tapes (gummed and pressure-sensitive). Friction
closures, screw caps, and locking devices are used to close and seal cans
and similar containers.