Abstract: A length of envelope material adapted for being fed to an envelope-forming machine in which the material comprises a succession of envelope units in an unbroken row wound in the form of a roll with a succession of windings. Each envelope unit has a transverse fold line dividing the unit into two halves along which separated units can be respectively folded to form respective envelopes. Each envelope unit has a window opening and a transparent cover on the opening. First strings of glue are provided on each unit for joining the halves thereof together after folding along the fold line. Further strings of glue join the transparent cover to the unit. The strings of glue and the transparent cover are of respective thicknesses to form a uniform elevation at one side of the material of each unit. The diameter of the roll in which the length of material is wound corresponds to the dimensional length of each unit and the thickness of the glue strings and covers so that the roll is substantially cylindrical.

Abstract: There is disclosed a machine for producing an item of mail essentially consisting of an enclosure and an envelope therefor. The enclosures are successively fed to a folding station of the machine by a conveyor. The folded enclosures are conveyed to an insertion station of the machine to be readied for insertion into an envelope and are then conveyed to an enveloping station of the machine. Envelope blanks are successively fed by a second conveyor to the enveloping station and wrapped in that station about enclosures, thereby forming an envelope for the enclosures. The first conveyor then feeds the envelopes with the enclosures therein successively to a sealing station; a franking station and a collecting station.