Abstract: Envelopes, particularly an envelope for mailing magnetic cards. The envelope includes a lower sheet of paper having an opening through which the magnetic card is exposed, a transparent film adhering to the rear surface of the lower sheet so as to cover the opening, and an upper sheet of paper mounted upon the lower sheet to cover the opening such that a magnetic card enclosure is defined by the upper sheet and lower sheet to receive and hold the magnetic card within the opening and such that the presence of the card within the envelope may be confirmed through the transparent sheet.