Collodion wet plate negatives

Gelatin dry plate negatives

Albumen silver photographs

ALBUMEN SILVER PHOTOGRAPHS

Sweet printed all of his photographs onto albumen silver printing-out paper. The albumen printing-out process was invented by Louis-Desiré Blanquart-Evrard in 1850 and it remained the most popular type of print until well into the 1890s. Photographers often created their own albumen silver paper by floating a sheet of thin paper on a bath of albumen solution. In the early days most photographers made their own albumen solution by beating equal parts of egg white and water with salt, glacial acitic acid and ammonium chloride or sodium chloride. Once the mixture had been converted to a froth it was allowed to settle in a covered container for 24 hours before being strained through muslin. It was then aged in a cool place for a week and would remain useful for several weeks after that.

The next step was to coat paper with the albumen solution by floating it on a tray of the liquid and then hanging up to dry. The paper was then sensitised in a bath of crystalised silver nitrate. Sweet could adjust the time and chemical additives to the bath to produce more brilliant prints and avoid discolouration. The paper was then ready to make a contact print from a glass plate negative. During Sweet's time all albumen paper was of the printing-out variety, used for making contact prints the same size as the glass plate negative. It was only much later that developing-out paper was used. The developing-out process used both chemicals and light to produce a positive image on paper from a negative. Developing-out papers could be used for contact printing and for enlargement but did not become popular until late in the 19th century. In the printing-out process, used by Sweet, the positive image was formed using only light, without any chemical development. Daylight was the only practical light source for this process and prints were often made out of doors or under a large skylight.

The contact print was made by placing the negative, collodion-side up, in a printing frame and laying the albumen paper face-down on top of the negative. A piece of chamois leather or soft cloth was placed over the paper to keep it in position when the doors of the wooden printing frame were closed over the top. The base of the printing frame was made of glass so that when it was stood at the window, on an outdoor printing rack, or under a skylight, the light would pass through the glass, the negative and onto the albumenised paper. Captain Sweet had to judge the strength of light and the exposure time according to the density of the negative (a better print is achieved from a dense negative if it is exposed under diffused light). He would take the frame into a shaded corner to check on the print. Once the desired result was achieved the print was taken to the darkroom where Sweet washed the print in a pail of water, moving it around for five minutes and then washed it again in fresh water. This process was repeated three times before toning the print.

Gold toning was the most popular in the nineteenth century. It increased image permanence and shifted the yellowy-brown colour of albumen prints to a cooler, more pleasing, hue. A variety of recipes for gold toning solution were available to the photographer, the simplest being one grain of pure chloride of gold, 8 oz. of distilled water, carbonative soda to neutralise acidity and two drachms of alcohol. Other recipes utilised gold and potassium or gold and uranium as well as a variety of other ingredients. The toning bath was warmed and the prints passed under hot water before submerging them in it. Once the colour changed Sweet removed the print, washed it in hot water and then immersed it in a fixing bath of hyposulphite of soda, water and alcohol. The print was washed again to remove all of the fixing solution and finally immersed in a tub of clean water for several hours. The water was constantly refreshed with a running stream, if possible, and the prints turned over frequently. The print was finally dried and mounted. Sweet's albumen silver paper was extremely thin and all prints were mounted on either card or a secondary paper support. Sweet always trimmed his prints carefully before sticking them to their mount with gum arabic or starch.

All sorts of variations were possible within the albumen printing process. A description of these can be found in John Towler's 1864 book, The Silver Sunbeam, which is available at albumen.stanford.edu. Instructions for photographers wanting to replicate these processes today can be found in James Reilly's 1980 publication, The Albumen & Salted Paper Book: the history and practice of photographic printing 1840-1895, which is also available at albumen.stanford.edu.

© Karen Magee 2008 - 2009