CDV or Carte de Visite photographs are small albumen (made with egg white) photo prints that were developed on thin paper. They were mounted on a heavier cut cardstock measuring about 2 1/2 by 4 inches.
CDV History: A Frenchman, Andre Disderi, received a patent for CDV's in 1854, which allowed 8 negatives to be taken by a camera onto an 8 x 10 plate. First introduced in the US in 1859, at the time of the start of the Civil War, CDV's were produced in the millions. The ease of size and paper format of this newfangled photograph allowed the CDV to be sent through the mail, a great benefit from the heavily glassed and protected and cased ambrotype and daguerreotype photos that were previously available.
Carte de Visite photographs are direct descendants of the Victorian Calling Card, thus the name, which translates to "visiting card". The Victorians were passionate "card" collectors, and it is reported that Queen Victoria filled between 35 and 100 CDV carte albums with CDV's she had personally collected. Her husband, Prince Albert, was an avid early photographer, with a photographic darkroom set up in Windsor Castle. England reportedly had annual sales of CDV's into the hundreds of millions. Although directed by her staff to consider taxing CDV sales, she refused, saying she wanted all the classes to delight in the hobby without being burdened by the government.
These cards are wonderful collectibles of a time gone by!