Here is an exerpt from Harper's Bazaar, ca. 1868: "Visiting cards for the coming season are of unglazed card board, large and almost square. Tinted cards, especially buff, are fashionable. The lettering is in old English text, or in script. The expense of fifty cards is $3.50.
One corner of the card is turned down to denote the object of the visit. In different cities a different signification is attached to these broken cards. We give the custom of New York society. On the left hand upper corner the word Visite is engraved on the reverse side. This corner is turned downed, displaying the word on the front of the card to signify that an ordinary call is made. On the right hand corner is Felicitation, to be used when making a visit of congratulation on some happy event, such as a marriage, or the birth of a child. On the left lower side is Conge, or Good-by. The remaining corner is marked Condolence."
Calling cards fall into the antique category of "ephemera", or paper collectibles. Related categories are calling card cases and calling card receivers. Card receivers held cards left by visitors who called while the mistress was out or 'not receiving'.