CDVs were traded among friends, and acquiring the CDVs of such famous people as Napoleon or Sojourner Truth was also popular in Europe and America, giving rise to the expression "cardomania." During the American Civil War these were enormously popular, allowing soldiers to carry images of their loved ones and to send their own images home.
CDVs were typically about 63 x 100 mm in size, or 2 1/4 x 4 1/4 inches, sometimes described as 2 1/2 by 4 inches. Many have the photographer's identity on the back; if you have one of these you are lucky if someone pencilled in the name of the subject of the photograph. Many were not labeled and are difficult to identify now.
The photographic process used a mixture of egg whites (thus the name "albumen print"), silver nitrate and sodium chloride to make the image.
The carte de visite photograph was supplanted by other methods including the tintype and cabinet cards, both usually larger in format.
