This invention is in the field of stationery and particularly remailable envelopes.
The concept of providing an envelope that can be closed and mailed and one whereby the receiver may then open the envelope to obtain its contents and use the same envelope for a return mailing is old and many attempts have been made to provide a satisfactory envelope capable of such use. It is desirable to be able to use the same envelope for return mailing to conserve paper, which becomes an expensive item where a great number of mailing are made from, for example, business establishments in billing their customers. It is further desirable that the first mailings be capable of being handled, that is, formed into an envelope stuffed with an enclosure and closed for mailing all by automatic machinery. It is further desirable that such mailings be capable of being reused for return to the sender.
An example of a returnable envelope is shown in the patent to Harvey No. 877,330 where the main panel of his envelope is provided with interlocking end flaps and a top and bottom flap. For the first mailing the bottom flap is folded up over the end flaps, then the top flap is folded downwardly and adhered to the bottom flap by adhesive provided on one face of the envelope material. The bottom flap is provided with adhesive material on the other face of the sheet so that it underlies the top flap when the latter is sealed for the first mailing. The recipient opens the letter by severing the top flap along the edge of the adhesive material and the envelope can then be used for remailing by reversible folding of all flaps against the other face of the sheet material and the bottom flap then is folded last and its adhesive material used to seal the envelope. In both the first and second mailings, however, the adhesive is permanent and the flap must be actually severed to provide access to the contents thus leaving its severed edge inside the remailed envelope.