AIC Preprints. May 1980. pp.93-98.
Research Associate, School of Photographic Arts and Sciences, Rochester Institute of Technology, One Lomb Mem. Drive, Rochester, N.Y. 1k623
Albumen prints are a variety of photographic paper print in which a finely divided silver and gold image is dispersed in a matrix of egg white. Such prints constitute by far the largest category of objects in 19th century photographic collections. Albumen paper became the most widely used photographic printing material about 1855, and remained so until 1895; it did not disappear completely from photographic practice until the 1920's.
The span of time during which albumen paper predominated in photographic usage represents not only an important formative period in photographic aesthetics and technology, It is also the era during which photography first began to be Integrated into a wide range of human activities, thus becoming an influence on the culture at large. This occurred in ways which we are only now beginning to appreciate. One ongoing example is our changing evaluation of the photographs of the American West and American Indian peoples; these images shaped attitudes toward the West at the time they were made--and still do--only now their power is magnified because for us, they embody both artistic achievement and deep historical significance.
Many other examples could be cited which would illustrate the growing Importance of 19th century photographs as cultural property. In most cases albumen prints are the primary original artifacts which constitute this cultural heritage. Therefore the conservation of albumen prints is one of the principal concerns in the whole field of the conservation of photographic materials.
Unfortunately, albumen prints as a group merit the urgent concern and attention of conservators. Very few survive in original condition. Approximately 85% of extant albumen prints suffer from the presence of a yellowish-brown stain in the highlights (nonimage areas), and almost as many exhibit overall image fading, with an accompanying shift in image color from purple or purplish-brown to a sickly yellowish-brown. Deterioration often includes a partial or severe loss of highlight detail. The staining, fading and color change may range from slight to very severe, but the extent of deterioration In albumen prints as a whole Is much more advanced than in nearly every other variety of photographic paper, including types which pre-date albumen papers
The albumen printing process Is closely related to the earliest known type of photographic paper, William Henry Fox Talbot' a famous "Photogenic Drawing" process, disclosed to the world on February 21, 1839 (1). Talbot prepared his photographic paper by soaking fine writing paper In a dilute solution of sodium chloride. After drying, the "salted" paper was sensitized by brushing on a strong silver nitrate solution. When the sensitized paper was placed in sunlight, an image of metallic silver was formed.
The first use of albumen in photography occurred only a few weeks after Talbot published the details of his process. An experimenter identified as "H. L." described a printing process using paper coated only with a mixture of equal parts of egg white and water, sensitized as usual with silver nitrate solution (2). Such paper contained no chloride, but depended instead on the light sensitivity of the coagulum formed in the reaction of silver ions and egg white proteins. A similar method was published by Robert Hunt in l831. This kind of albumen paper :Lacked the beauty and sensitivity of the plain chloride papers, however, and it found very little use in :photographic practice.
Some ten years after Talbot's publication a French photographer, Louis Désiré Blanquart-Evrard, greatly improved the albumen printing process and brought it to its most useful and historically important form. Blanquart-Evrard had enjoyed limited success using albumen for paper negatives, but be discovered that when the chlorides of ordinary salted paper were dispersed in egg white, a positive printing-out paper of extraordinary detail and contrast was produced. Notice of the discovery was first published in the Bulletin of the French Academy of Sciences on May 27, 1850 (3).
Photographers around the world responded quite favorably to the new printing process, and by 1855 albumen paper had become the dominant photographic printing material. The rapid acceptance of albumen paper was largely due to a simultaneous revolution in the techniques used to produce photographic negatives. The wet collodion negative process, with its long density range and very fine detail, was a great advance over earlier paper negative methods and also gained wide acceptance in the early 1850's. Wet collodion negatives demanded a printing paper capable of more detail and contrast than the older plain salted papers could provide. The albumen print possessed increased detail and contrast because the image resided in the compact layer of albumen on the print surface, instead of deep within the fibers of the paper.
During the 25 year span 1860-1885 albumen paper was in virtually exclusive use as the general-purpose printing paper of photography.. A large industry grew up to supply the enormous demand for the product. Although commercially prepared albumen paper was available before 1855 (4), most photographers albumenized their own paper until the mid 1860's. After that time the usual practice was for photographers to purchase factory coated paper, although this still required sensitization by the user immediately before printing. Pre-sensitized paper came on the market in 1872 and became very popular with amateur photographers in the 1880's and 1890's. Professional photographers continued to sensitize their own paper because of the lower costs involved.
The center of worldwide albumen paper production was Dresden, Germany. Located near the sources of suitable raw paper stock, Dresden also enjoyed an abundant supply of low cost eggs and low cost labor. Nearly all the tasks In the production of albumen paper were performed by women, and very few of the manufacturing steps were mechanized. Coating of the paper was done by floating large sheets of paper on a tray of albumen, one sheet at a time. Albumenized paper had a long shelf life and was exported from Dresden to all parts of the world. The Dresden producers allowed the albumen to undergo a process of bacterial fermentation for several days at ca. 50°C., in the belief that this produced albumen paper of higher gloss and also made gold toning easier. Producers in other parts of Europe and in America did not employ the fermentation process, and every photographer could readily tell German paper from other kinds simply by smelling it.
Albumen paper was inherently "soft-working", i.e., of low contrast, and could not be easily adapted to produce good prints from negatives of low contrast. When the gelatin dry plate replaced the wet collodion negative process, the average contrast of negatives declined; amateur photographers (and many professionals) frequently encountered difficulties in making acceptable albumen prints from dry plate negatives. In the mid and late 1880's several new kinds of printing-out papers appeared and began to challenge albumen paper in the marketplace. These were chiefly gelatin and collodion emulsion type printing-out papers, which were pre-sensitized and possessed the advantages of higher inherent contrast, longer shelf life and higher gloss (considered a great virtue at the time). The issue of permanency was also a factor in the obsolescence of albumen paper, since the poor performance of albumen paper as an archival material was well known at the time. Manufacturers of gelatin and collodion papers made sure by their advertising campaigns that the durability of their products was communicated to the buying public. Time has substantiated their superiority with respect to albumen paper, and indeed collodion papers have proven to be exceptionally stable. Gelatin and collodion papers outsold albumen paper after 1895, although some photographers continued to prefer albumen paper for Its long tonal scale, unique surface qualities and characteristic image color.
Preparation of albumen paper began with fresh eggs. Only the clear white was used, and contamination from blood, yolk or the stringy tissues known as chalazae was carefully avoided. An appropriate amount of chloride (usually l¼% ammonium chloride) was added and the albumen was beaten to a froth. This mixture was allowed to stand until it had settled back to a liquid state, then was filtered through muslin. If a fermentation step was employed, then the chlorides were added after the beating, settling and fermentation were completed.
The paper stock used for albumen paper was necessarily a lightweight rag stock of exceptional quality and purity. The rawstock needed to be thin enough to remain pliant when coated with a layer of dried albumen, since sensitization was also accomplished by the delicate process of floating. Stiff paper would have been Impossible to float successfully. For most of the 19th century only two paper mills in the world could consistently produce rawstock of the requisite quality, the Blanchet Fréres et Kleber Co. in Rives, France, and Steinbach & Co. in Malmedy, Belgium. Both rawstocks were machine made and sized with a mixture of starch and resin soaps. One analysis of Rives rawstock conducted in 1904 showed it to be composed of 85% linen and 15% cotton fiber (5). The common sheet size was k6 by 58 cm, and the most common basis weight was 10 kg per ream (480 sheets).
The time of floating on the albumen solution was about one minute; the sheets were then taken to a warm loft for drying, because a faster rate of drying imparted higher gloss to the paper. A great deal of the paper sold during the 1880's and 1890's was "doubly albumenized", i.e., floated twice to obtain maximum gloss. Another common practice was the addition of aniline dyes to the albumen solution. Tinted paper was mainly used for portraits, and the most popular tint appeared to be pink, but various shades of purple, blue and even green were also used. Because the dyes had such poor lightfastness--especially in such dilute solution--most of the dyed paper is difficult to recognize today.
Sensitization was accomplished by floating the albumen paper on a silver nitrate solution for 2-3 minutes. Paper sensitized on a plain silver nitrate solution yellowed (by the spontaneous reduction of metallic silver) within one or two days, so sensitization, printing and processing were usually done on the same day. The addition of up to 5% citric acid to the silver nitrate solution extended the useful life of sensitized paper up to a maximum of several months. This was the basis of the commercially produced "ready-sensitized" papers. Printing was usually carried out not in direct sunlight but in diffused daylight, since direct sun tended to produce "flat" prints, unless the negative possessed a very long density range.
The fact that albumen prints are produced by a "printing-out" mechanism (no chemical developer is necessary) has some important consequences for the appearance and permanence of the resultant prints. The fundamental silver image particles produced in all silver printing-out papers are very much smaller than the image particles produced by the action of a chemical developer. Because of the phenomenon known as light scattering, after fixation the smaller Image particles of printing-out papers do not appear neutral black, but instead appear brown, red or even yellow. For this reason a toning step was included in the processing sequence of most printing-out papers, wherein a deposition of gold or platinum (or both) was made on the silver image. Gold toning of albumen paper produced the familiar purple or purplish-brown image colors found in historical prints. Platinum toning was not used with albumen paper, although it was extensively used with collodion printing-out papers.
Another important consequence of the very small image particle size In albumen paper is the resultant huge increase in the surface area of the particle relative to Its total mass. Because of this enormous surface development, the Inherent vulnerability to superficial chemical attack is much greater in albumen prints than in most develop-out papers. All the chemical processes of deterioration must begin at the surface of the grain and therefore an increase in surface area allows the reactions of decay to proceed more rapidly.. In addition, since the image color in albumen prints is a result of the particle size (and to a lesser extent the surface characteristics of the particles), then a small change in size induced by chemical attack has an immediate effect on the color and density of the print.
One of the primary sources of chemical attack on albumen print images is the presence of residual fixer and residual chemical products of fixation. Albumen prints were fixed in a strong solution of sodium thiosulfate, then washed in water to remove the sodium thiosulfate and silver-thiosulfate complexes. Although sodium thiosulfate is effective in removing the silver chloride from albumen prints, it was discovered as early as 1859 that some silver remained in white (non-image) areas of albumen prints. This is not the case when gelatin or collodion prints are fixed in sodium thiosulfate, and the retention of silver in albumen prints seems to be related to the interaction of silver and egg white proteins. The conversion of this silver to silver sulfide is the immediate cause of highlight yellowing in albumen prints. Highlight staining may also be caused by incomplete fixing or washing; in this event the staining will be all the worse because of the extra silver retained by the albumen itself.
Image fading and detail loss are characterized in albumen prints by a change in image color as well as a loss In density. The conversion of the Image silver to silver sulfide seems to be the primary mechanism of print deterioration. The breakdown of residual fixer Is one of the primary sources of the reactive sulfur necessary for this chemical change. Other possible sources of sulfur include atmospheric pollution and Improper mount boards and mounting adhesives. So many albumen prints have undergone a shift in image color (perhaps 80-90% of extant prints), that it is sometimes difficult to realize the full extent of the deterioration which has occurred,; few prints can serve as a reference to indicate the original appearance of albumen prints. Research is now being undertaken to understand more fully the causes and mechanisms of albumen print deterioration and to develop new approaches to the preservation of these materials.
1. W. H. Fox Talbot, "An Account of the Processes Employed in Photogenic Drawing", The Athenaeum, No. 539 (Feb. 23, 1839), p. 156.
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