Cartes de Visite (CdV) – The carte de visite (French: visiting card), or CdV, was a type of small photograph which was patented in 1854. It was typically made of an albumen print, which was a thin paper photograph mounted on a thicker paper card. The size of a carte de visite is roughly 2-1/8″ × 3-1/2″ mounted on a card sized 2-1/2″ × 4″. The photos were exchanged among friends and became very popular in the Victorian era.
Cabinet Cards – By the early 1870s, the cartes de visite began to be replaced by “cabinet cards”, which were also usually albumen prints mounted on cardboard backs measuring roughly 4-1/2″ x 6-1/2″. Cabinet cards remained popular into the early 20th century, when home photography became a mass phenomenon with the introduction of the Kodak Brownie camera.
Stereoscopes – A stereoscope is a device for viewing a stereoscopic pair of separate images, depicting left-eye and right-eye views of the same scene, as a single three-dimensional image. While the original viewers were first invented in 1938, the popular hand-held stereoscope dates from the 1850s, and consisted of a pair of prismatic lenses and a wooden stand to hold the stereo card.