carte-de-visite.
Louis-Désiré Blanquart-Évrard invented the process using albumen (that’s the clear gelatinous part that surrounds the yolk) in 1850, and it became the most popular method for photographic printing in the 19th century. Paper was laid on a mixture of albumen and salt. When it dried, it made a glossy coated paper. The process could be used with any type of negative. It yielded precise images (partly because the image actually floated on the surface), and it was inexpensive. It was so popular that early on, commercial producers kept chickens on site!
It is an important vehicle for pigment.