When folding a postal box, the key is to use the folding lines in the correct order. Often, the flaps at the sides are folded over the remaining flaps, holding them in place. A postal box with locking tabs is easily closed and opened thanks to its in-built locking tabs (wings). A peel-and-seal type of postal box is closed thanks to an adhesive strip. The box can be opened by using the built-in "tear off-strip".
Check out our video tutorial “How to fold a postal box”