Formular stationery
![1938 formular registered envelope from the Bahamas. Note that although there is an indicium for the registration fee, there is no prepayment of postage. An adhesive postage stamp would have to be applied to send it. This and many other envelopes were made from thick paper and lined with glued gauze to make it stiffer and non-transparent.](/Images/godic/202501/14/RegisterLetterEnvelopeBahamas19385651.jpg")
![1943 Air Mail Letter Card. The fact that it has an adhesive stamp and no prepayment of postage means that it is formular and not postal stationery.](/Images/godic/202501/14/Air_mail_letter_card_19435651.jpg")
The term formular (often spelled formula) is an adjective applied to envelopes, cards and aerograms, etc., produced by postal authorities or to their specification, but bearing no imprinted or embossed stamp or other indication of prepayment of postage.