Thread to open envelope by tearing - is glued into envelope flap crease leaving short protruding end

摘要

The letter is torn open by means of a thin thread of any suitable material, flued into the crease of the envelope flap (6). A short length (1a) protrudes from the envelope, with which the thread is despatched as an integral part. The non-protruding thread end (2) can have a small piece of paper glued over it, or the whole length of the thread inside the envelope can be covered by a paper strip. The protruding end of the thread can be a thickened portion, typically of plastic.