The earliest photographers faced a dilemma spurred by the near-simultaneous invention of two very different kinds of photographs: daguerreotypes and salted paper prints. Daguerreotypes were cherished for their extraordinary detail and beauty but lacked the ability to be easily reproduced. Alternatively, many copies could be made from a single paper negative but the resulting prints lacked the exacting resolution of daguerreotypes. Paper would eventually become the standard for pre-digital photography, but refinements to Talbot’s process were necessary before widespread adoption could take hold. By midcentury, the wet collodion and albumen processes provided the necessary improvements to replace the salted paper print, greatly expanding the appeal and reach of photography.
The translucency of paper posed an obstacle for relaying detail from negative to positive. This problem was solved in 1848 by the British sculptor-turned-photographer Frederick Scott Archer, who invented the wet collodion process, a means of producing negative images on glass plates. His technique centered upon a collodion emulsion that began with gun cotton (nitrocellulose), a combustible material used in munitions and explosive devices, dissolved in alcohol or ether, and mixed with bromide and iodide salts. This sticky mixture was carefully poured on a glass plate and allowed to set— but not dry. In the dark, silver nitrate was added to sensitize the emulsion to light. The plate was then exposed while still wet— hence “wet-plate” and developed in a bath of pyrogallic and acetic acid (later ferrous sulfate was used). The resulting image was fixed with sodium thiosulfate and washed. Often a layer of varnish was added for protective purposes. Once dried, contact prints could be made from the negative. As would be expected, the transparency of glass negatives made them much more amenable to transferring detail to their positive prints.
The number of glass negatives produced in this manner is a testament to both the technical skill and dedication of early photographers. Some of the most important figures of 19th-century photography— Timothy O’Sullivan, Carleton Watkins, and Francis Frith— traveled with wagons converted into darkrooms to document Civil War battlefields, the peaks of Yosemite, and the monuments of the Middle East, respectively. As the photographs produced using this method were made via contact printing, glass plates up to 18 x 22" were miraculously preserved despite their often perilous journeys home.
Numerous photographers attempted with varying degrees of success to create a dry collodion process by adding sticky substances to the sensitized plate to keep it wet longer. The concoctions used read like a Sunday brunch menu: honey, raspberry syrup, and beer—among other less appetizing substances. In the end, gelatin would be the most successful base used for photographic emulsions, but that would have to wait for the British photographer Richard L. Maddox, in 1871.
Just as the addition of a collodion emulsion to glass plates benefited image quality, the development of a viable emulsion for paper prints greatly increased the fine detail of resulting prints. The characteristic haziness of salted paper prints was, in part, due to the porous nature of its support. The paper absorbed silver salts, ceding detail to the materiality of its base.
In 1850, the French photographer Louis Désiré Blanquart-Evrard introduced the albumen paper printing process, a means of creating photographs capable of rendering much greater resolution than salted paper prints. Blanquart-Evrard’s technique relied upon an emulsion made of whisked and filtered egg whites (albumen) and ammonium or sodium chloride applied to paper. By floating paper in the mixture, the pores of the paper were filled, resulting in a smooth surface. After drying, the paper was then floated in a bath of silver nitrate to sensitize the paper. When paired with glass negatives, a remarkably sharp image could be contact printed onto the paper. Gold chloride was often applied to tone the image, lending a distinct aesthetic to the prints. Finally, the image would be fixed using sodium thiosulfate and washed in water. While salted paper prints were matte in nature, albumen prints exhibit a characteristic glossy sheen.
Equally influential was Blanquart-Evrard’s invention of the carte-de-visite. Patented in 1854, the carte-de-visite was a small visiting card with an albumen print attached. Blanquart-Evrard used a specialized camera with multiple lenses to produce several portraits on a single glass negative, reducing the cost of the process and product. If a sitter blinked or moved during an exposure, several other options would be available to select from. Likewise, different poses and attire could be incorporated into a shoot for variety.
First popularized as a means of forging personal connections—much like a business card today—the carte-de-visite would quickly create its own market for the collection of photographs of not only known acquaintances but also celebrities. Unlike delicate daguerreotypes, they could be easily sent through the mail, furthering the photographic footprint of ambitious individuals. As popularity surged, composite cards of celebrities or politicians were created specifically for large-scale distribution. For the first time, photography was used on a mass scale to familiarize the public with the faces of its leaders. Specialized albums were created to store and share carte-de-visite collections, paving the way for family photo albums and future trading card hobbyists.
Photographers interested in the wet collodion process today face the challenge of working with somewhat difficult materials to acquire. While B&H carries Photographers’ Formulary Collodion, it must be ordered in advance and picked up in the store. For photographers who already have access to the necessary chemistry, Modern Collodion makes a Silver Bath Tank, Fixer Bath Tank, and Wet Plate Drying Rack for processing.
Have you worked with wet collodion negatives? Albumen printing? Share your wisdom in the Comments section, below.