Postcards are either officially produced as postal stationery normally including an impressed postage stamp.
Private picture postcards began to appear in the 1890s as printed pictures on the reverse side of postal stationery. In the same period photographers such as Barnett printed pictures on one side, leaving the front for an address. Such cards could be sent at letter rate, until 1904 when a general postcard rate was approved by the Universal Postal Union (U.P.U.) for internal and international postage.
Cheaper postal rates for picture postcards led to a boom in their use throughout the world. Transvaal was no exception and continues to appeal to anyone fascinated by what a city or a small settlement looked like more than a century ago.