Reilly, James M. The Albumen & Salted Paper Book: The history and practice of photographic printing, 1840-1895. Light Impressions Corporation. Rochester, 1980.

Chapter Eleven
The Question of Permanence

THE LAST PRINT IN SILVER
'Tis the last print in Silver
Left mould'ring alone,
All her gold-toned companions
Are faded and gone.
No print of her kindred,
Albumen, is nigh,
To reflect back her jaundice
So sad to the eye.
I will leave thee, thou lone one,
To vanish away
And to all fellow-workers
With confidence say
Go, print now in Carbon,
Or platinum choose
As long recommended
By friend Jabez Hughes.
So soon may all follow
A 'Permanent way,'
And from out of our albums
No prints fade away.
For when Albumen's yellow,
and Chloride is flown,
Platino and Carbon
Shall still hold their own.
--Edgar Clifton, 1887¹

The question of the durability of albumen and salted paper prints is of great interest to collectors, curators, librarians and historians, as well as to modern workers of these processes. This chapter deals with the historical record regarding the permanence of albumen and salted papers, and reviews the theoretical and practical considerations in guaranteeing maximum print stability.

Historical Review

THE ERA OF SALTED PAPERS 1840-185 5

During the late 1840's the initial burst of enthusiasm and interest of the general public for the new marvel--photographic pictures--had hardly worn off before the fading and staining of paper prints threatened to discredit photography on paper altogether, and reduce it to the status of a scientific curiosity. While daguerreotypes seemed to be fairly stable, the image on salted paper prints in many cases faded to near invisibility, and all sorts of complaints of staining and mottling were heard. It soon became apparent that something in the preparation and/or storage of a high percentage of photographic prints was leading to their speedy destruction. For various reasons the daguerreotype process was the most widely used for portraiture, but some commercial portraiture was attempted using Talbot's calotype process. The high prices paid for this service made the rapid fading of the results especially annoying to the patrons,² and the ensuing public complaints--together with Talbot's patent restrictions--effectively ended the commercial possibilities of calotype portraiture.

The real advantage of Talbot's negative-positive system of photography over the daguerreotype was the capability to make multiple copies of the image. Talbot himself took advantage of this in bringing out the first commercially offered photographically illustrated book, The Pencil of Nature, issued serially during the years 1844-1846. This was the first of several publications illustrated with salted paper prints that Talbot produced at his "Reading Establishment," where he had hired Nikolaas Henneman and Thomas Malone to carry out the actual printing. The prints made at Reading became some of the most visible and notorious examples of the instability of salted paper prints. A great many of the problems of the Reading prints may have stemmed from insufficient washing; Henneman himself stated in a discussion at a meeting of the Photographic Society of London in May, 1856, that:

We all know the "Pencil of Nature" alluded to by Mr. Malone; of those prints I made twenty-five in one batch; they had only three washings. Some of them remained perfectly good, as if they were printed but yesterday, and others have totally failed.3

Today of the surviving prints made for The Pencil of Nature, barely a handful are not very badly faded, and apparently none survive in original condition. Many salted paper prints made by amateurs at approximately the same period have survived much better than The Pencil of Nature prints, pointing up the frequent occurrence that mass-produced images get poorer fixing and washing than individual efforts.

Mostly for reasons of ease of operation and public preference, but partly also because of the worry over fading, the daguerreotype retained complete dominance of commercial portraiture through the early 1850's. Meanwhile, photographers struggled to improve both the paper negative (which had already proved more adaptable to outdoor photography than the daguerreotype) and the paper print. Concern over print stability grew to become the single most pressing problem in photography, especially after advances in negative technique in the late 1840's and early 1850's made the whole negative-positive approach to photography so much more attractive.

Although progress had been made in determining the causes of print fading, it was still very uncertain whether any given print would survive for more than a few years. Determination of the exact causes of fading was complicated by the vast number of different base papers, binder materials and processing chemicals in use at that time. One fact, however, was very clear; photographic paper negatives--in which the image was produced by development--had a much better record of durability than the various kinds of printing-out papers used for positives.⁴ Nevertheless, the image color, familiarity, superior tone reproduction and controllability of printing-out papers insured their continued use while the search for improved print stability went on.

In 1855 the Photographic Society of London established a committee to investigate the causes of print fading. The committee asked for samples of prints made by any and all processes to be forwarded to them for examination and testing. In its report the committee stated:

Hence it appears that the most ordinary cause of fading, may be traced to the presence of sulphur, the source of which may be intrinsic from hyposulphite left in the print, or extrinsic from the atmosphere, and in either case the action is much more rapid in the presence of moisture.5

The "Committee Appointed to take into Consideration the Question of the Fading of Positive Photographic Pictures upon Paper" was first class, both in its eminent personnel and the accuracy of its conclusions. Its report spelled out for the photographic community several of the leading causes of print instability, and its practical recommendations laid stress on two important procedures: thorough washing of prints after fixing, and the employment of gold toning. Although these findings were hardly novel or completely original to the committee members, the authority the committee's work put behind these recommendations was very beneficial to the general practice of photography at that time.

During the same year--1855--another important key to print stability was discovered and published by two French photographers, Alphonse Davanne and Jules Girard. These two men contributed immeasurably to the advancement of photographic science by systematically examining all aspects of the printing process with the most up-to-date chemical and empirical methods of their time. They analyzed for sulfur content prints fixed in fresh sodium thiosulfate and others fixed in "old hypo," and confirmed the suspicions of many photographers that only fresh, pure thiosulfate solutions--followed by thorough washing--left prints uncontaminatedwith sulfur after processing. By subjecting test prints to high humidity levels they showed that the sulfur contaminated prints "rapidly turn yellow and at last vanish."⁶

THE INTRODUCTION OF ALBUMEN PAPER 1850-1860

Although the work of the printing committee of The Photographic Society of London and of Davanne and Girard (as well as other independent investigators) was successful in identifying the primary causes of fading, the problem of print instability did not end. In the mid 1850's a transition from salted papers to the new albumen paper took place, and albumen prints brought new difficulties in fixing and washing, mostly because of their thicker and less permeable image layer. The adoption of albumen paper meant that a new technology had to be learned, and naturally it required several years before the peculiarities of albumen paper became familiar to both photographers and the newly organized albumen paper manufacturing companies. The working methods for plain salted papers did not exactly coincide with those of albumen paper, especially in the sensitizing and toning steps. No doubt as a result of unfamiliarity with the material and the general uncertainty over proper fixing and washing procedures, a great many early albumen prints now exhibit advanced yellowing and fading.

The point which was most stressed in the journals of that period was the necessity of thorough washing, and it seems that probably most photographers took pains to wash their prints as best they could. It appears in retrospect that apart from the use of exhausted fixer solutions, the most serious detriments to permanence of prints during the decade of the 1850's were additives (mostly for their presumed toning effect) to the fixing bath. A large category of such additives were described as "coloring agents," but merely had the effect of decomposing the sodium thiosulfate, so that a process of sulfiding of the silver image took place.

Gold toning, which had the endorsement of the most respected photographic authorities and was certainly a good idea in principle, was often the fatal flaw in otherwise good processing because of the manner in which it was applied; when photographers mixed gold chloride and "hypo" together, in many cases the acidity of the gold solution decomposed the sodium thiosulfate and liberated sulfur, which ultimately caused the prints to fade (see Chapters 8 & 9). This method of toning was known as the sel d'or method, and it was the most widely used approach to gold toning in the decade 1850-1860. When the solutions were fresh and the work properly done, the combined toning and fixing of the sel d'or method occasionally produced prints of excellent stability, but in ordinary practice the method had too many drawbacks and was finally replaced at the end of the decade by the vastly superior "separate" toning approach.

The new technique of separate toning in alkaline gold chloride solutions--followed by fixation in fresh, strong sodiumthiosulfate--was a great step forward that consolidated the advances in print stability made during the 1850's and allowed albumen paper to attain a much better record of resistance to fading than had been accomplished with the older plain salted papers. The new alkaline gold toners deposited more gold than the other toning methods, and this contributed to the resistance of albumen prints to oxidative fading. In addition to the protection offered by the gold, the albumen layer itself made a significant difference in protecting the silver image from oxidizing gases.

ALBUMEN PRINTS AFTER 1860

In the 1860's the old idea that the hypo bath was also a kind of "toning" bath finally gave way to the more modern view that its purpose was strictly to remove the light-sensitive substances remaining in the print. As the 1860's progressed the manufacture of albumen paper became more and more centralized in factories, and the overall quality of albumen paper increased as a result. Improvements in albumen coating procedures also resulted in glossier papers. Albumen prints from the 1860's were generally "salted" with 2-3% chloride, an amount considerably higher than was used later on in the 1880's and 1890's. This increased chloride content in the earlier prints on the whole resulted in slightly higher average print shadow densities, which in turn meant that relatively more silver was deposited to form the image. More image silver results in improved resistance to fading,⁷ and albumen prints of the 1860's and 1870's seem to have accumulated a slightly better average record of durability (in terms of resistance to image fading) than their weakly salted and scantily exposed successors in the 1880's and 1890's. The reasons for the shift in chloride content of albumen paper have to do with changes in the character of the negatives used, and are discussed in Chapter 6.

ALBUMEN VERSUS EMULSION-TYPE PRINTING-OUT PAPERS

By the 1890's a feeling of mistrust for albumen paper was growing, since a significant number of prints from previous years were already yellowed or faded. The yellowing was particularly objectionable, because while fading could be ascribed to poor technique, yellowing seemed almost intrinsic to the material. When the new emulsion-type gelatin and collodion printing-out papers were introduced in the late 1880's, their makers trumpeted the "undoubted permanence" of these papers as loudly as their "convenience." As emulsion papers gained ground in the marketplace, scathing denunciations of albumen paper appeared in the photographic journals. "Judging from the abuse heaped upon the innocent albumen print by many writers for the journals, a stranger from the planet Mars would doubtless wonder why it is not immediately suppressed ," wrote W. H. Sherman in the American Annual of Photography and The Times Almanac for 1892.8 "According to these writers," he continued, "the head and front of its offending is its want of permanency.

The relative merits of each type of paper were hotly disputed and exaggerated claims were made on both sides. The debate recalled the furor which accompanied the introduction of the gelatin dry plate, and many of the arguments put forth in favor of albumen paper were similar to those used to defend the old wet collodion process, namely that photographers were used to albumen paper and could turn out albumen prints easier and cheaper than with the new emulsion papers. The difference in the case of the printing papers, however, was the issue of permanency; not only was albumen paper inconvenient because of the necessity to sensitize it before use, it also had the undeniable tendency to yellow in the highlight areas. For a while the low price of albumen paper kept its sales strong, but by 1895 cutthroat competition among producers lowered the price of the gelatin and collodion printing-out papers⁹ and the outcome was clear: albumen paper began to be outsold by the emulsion papers and was on the road to obsolescence.

Ironically, at this time when the producers of gelatin and collodion emulsion-type printing-out papers were proclaiming the superior permanence of their product over albumen paper, they were also recommending combined toning-fixing baths, a circumstance that definitely did not maximize print stability. Many gelatin and collodion prints of this era are now in rather poor condition as a result of the "combined bath" (which long before had been repudiated for use with albumen paper), although after the mid 1890's many unfavorable reports on this technique discouraged professionals from using it. Apart from this difficulty, however, the gelatin and collodion printing-out papers lived up to their manufacturers' claims and have established an excellent record of stability, with collodion papers proving exceptionally stable. Although collodion printing-out papers have a thin emulsion layer composed of essentially the same material--cellulose nitrate--that has proven so impermanent and dangerous when used as a film base for sheet and motion picture films, there is absolutely no evidence to suggest that collodion paper prints are in any way dangerous or unstable.

Some of the defenders of albumen paper preferred it out of habit, while others argued that its long tonal scale and unique qualities of image color, surface, etc., were valuable in their own right, apart from considerations of cost and convenience. The modern reader is most apt to be sympathetic to this position, since today many people admire the "special" character of albumen printing paper in spite of yellowing of the highlights and the many instances of fading found in surviving prints. Many critics of albumen paper in the 1890's put forward the completely erroneous view that since such a large number of early albumen prints had faded, all albumen prints can expect the same fate sooner or later. The more well-informed of these speaking on behalf of albumen paper reminded the critics that back in the 1850's proper toning, fixing and washing procedures for albumen paper were not well understood.

Fig. 46. An 1899 advertisement for collodio-chloride emulsion type printing-out paper. The reference to "permanency" was directed at albumen paper users.

Highlight Yellowing in Albumen Prints

The most common form of deterioration of historical albumen prints is the appearance of a yellow or yellowish-brown stain in the highlights (non-image areas). While the severity of yellowing varies widely from print to print, it is probably safe to say that not a single albumen print survives from the 19th century without some degree of staining in non-image areas. Many prints, it is true, do seem to be pristine and unyellowed, but when compared side by side with a freshly albumenized (and never sensitized) sheet of paper, a noticeable difference will be perceived between the "paper white" areas in the freshly albumenized sheet and the historical print.

Most albumen prints do not require a comparison with a freshly albumenized sheet, because it is quite obvious that they have yellowed. Approximately 85% of extant albumen prints made after 1860 display what might be called "moderate to severe" yellowing, while the remaining 15% or so seem to have white highlights unless compared side by side with a white sheet of paper. For those albumen prints made in the 1850's the figures probably are closer to 95% and 5%. These figures are not based on any formal statistical sampling, merely on the accumulated experience of the author in examining prints and through discussions with curators and collectors A statistical study of a large collection of albumen prints with regard to the type and severity of print deterioration--including highlight yellowing--would be a most welcome addition to the literature of photographic preservation.

Yellowing of the highlights in albumen prints is sometimes independent of generalized image fading, i.e. the highlights have turned yellow but the middletones and shadows have remained apparently unchanged Highlight yellowing is so prevalent in albumen prints that it often serves as an important clue in their identification since the highlight yellowing phenomenon is peculiar to albumen paper and does not occur in quite the same way in otherwise similar gelatin and collodion papers

Severe highlight yellowing is accompanied in most cases by an apparent color shift and density loss in the image itself The original purplish brown color of many prints has lost density and faded to a sepia brown Loss of highlight detail is also common in such cases The image color may even assume a greenish tinge Indeed few albumen prints today at all resemble their original image color.

The time period required for the onset of highlight yellowing in an albumen print appears to vary considerably, and is probably affected primarily by the moisture level and temperature of the storage environment and the amount of residual thiosulfate and silver-thiosulfate complexes present. Many prints seem to have yellowed very quickly--within one or two years of processing--whileothers seem to have taken much longer. There is no guarantee that even today improper storage will not initiate rapid yellowing in the prints that have remained reasonably unyellowed up to this point. Photographic literature of the period 1860-1895 does contain numerous mentions and complaints about the yellowing of highlights in albumen paper, although it seems clear that nowhere near 85% of prints had yellowed to a "moderate to severe" extent during the period when albumen paper was still in general use.

CAUSES OF HIGHLIGHT YELLOWING IN ALBUMEN PRINTS

The probable origin of the yellowing phenomenon in albumen paper is the chemical bonding of silver to sulfur-containing side groups on the protein molecules of albumen, some of which have a very high affinity for silver. The silver bonded during sensitization to these sites on the protein is so tightly held that treatment in hypo is not sufficient to remove it. Thus a small amount of silver remains in all areas of a fixed albumen print; the conversion of this silver to silver sulfide is the immediate cause of the yellowing phenomenon.

The first published notice of the presence of residual silver in non-image areas of albumen prints was made in December 1859 by Davanne and Girard.¹⁰ In a communication on the general subject of the fixation of positive prints to the French Photographic Society, the two scientists noted that a 2% solution of potassium cyanide did remove all traces of silver from albumen prints, while strong solutions of hypo did not. They wrote:

These results present a certain importance; . . . they show that it is difficult to remove every trace of silver salt contained in albumenised proofs, and consequently, explain the difficulty which photographers often meet with in their attempts to obtain proofs on albumenised paper in which the whites shall be pure and well preserved."

They also noted that cyanide fixation had two serious drawbacks which virtually ruled it out as a practical technique: it attacked and severely bleached the silver image, and it was highly poisonous.

In 1866 Matthew Carey Lea, the famous American photographic scientist, also noted the presence of residual silver in albumen prints. He conducted a series of experiments to find an appropriate solvent for this retained silver, but with no success.¹²

The question was explored by the Englishman John Spiller, who wrote in a paper, which he read to the Photographic Society of Great Britain on Jan. 14, 1868:

My experiments went to prove that the metal was retained in the whites of the albumen print, and indeed in all parts of the coating, in the form of an argentic organic compound, colorless, unalterable by light, and comparatively insoluble in hyposulphites and other fixing agents. It could not be a simple sulphide, for the test by which I discovered its existence in the paper was the production of a brown stain upon moistening the white surface with sulphide of ammonium.¹³

Twenty-five years later two Englishmen, A. Haddon and F. B. Grundy, followed up on the inquiries made by Spiller by actually measuring the amount of silver retained in prints that were sensitized and fixed, but never exposed. These prints should have contained no silver at all, since they had no visible image. The results of their study were shocking, because they found that an unexposed print (that had been thoroughly fixed and washed) still contained nearly 5% of the silver left after sensitization and before processing.¹⁴ To demonstrate the significance of this finding they took an unexposed and fixed sheet of albumen paper and first converted the residual silver to silver chloride by placing the print in chlorine water; they then applied a solution of potassium nitrite to act as a chlorine acceptor and proceeded to print out an image that was nearly as intense as one printed in the usual way! They reported these disturbing findings in a series of articles in the British Journal of Photography in the mid 1890's."

If the assumption made by Spiller and confirmed by Haddon and Grundy is true, then the large amounts of "silver albumenate" present in all areas of albumen prints are very threatening to the long-term stability of these materials, since therefore the potential for very severe highlight staining exists in every print. The presumed mechanism of the yellowing is the formation of silver sulfide by reaction of the albumen-bound silver with labile sulfur supplied by residual fixer or atmospheric pollution. If a print was inadequately fixed or washed, then probably it will yellow in the highlights in addition to fading, and this kind of yellow staining can and does occur in gelatin and collodion as well as albumen prints.

Under such circumstances of high levels of residual fixer, albumen prints can be expected to display relatively more severe highlight yellowing than gelatin prints because of the extra silver available in the highlight areas to react with sulfur from the decomposing residual fixer. After 75 years (roughly the period of time that has elapsed since the last widespread use of glossy albumen paper) the highly fixer-contaminated albumen prints are no doubt already deteriorated and obviously little can be done of a preventative nature to preserve them. For these prints restoration by chemical means is the only hope, but this task is beyond our present abilities.

ASSESSING THE RATE OF YELLOWING AND FADING

At present we must concentrate on the prevention of further decay by striving to understand more completely the mechanisms of fading, yellowing and staining. As a first step it is important to assess whether the yellowing process is ongoing for all surviving albumen prints (as theoretically it would be, since some sulfur is present in the atmosphere of nearly every locality), and if so, at what rate. This cannot be done visually, and in fact it is a property of human vision that has probably kept the problem of highlight staining of albumen prints from receiving more attention than it has.

The human visual system has a built-in mechanism that automatically seeks out the lightest area in a photographic print and pegs that as a "reference white;" this adaptive mechanism can lead an observer to believe that the highlights of a print are brighter than they are unless a side-by-side comparison is made with a "true" white. It is indeed fortunate for our appreciation of albumen paper photographs that we have this built-in ability to compensate for stained highlights, since otherwise a majority of albumen photographs would seem excessively "flat" and lifeless.

On the other hand the imperceptibly slow fading process and staining of the highlights in historical albumen prints may be proceeding at a rate which will lead to very severe image deterioration long before the paper and albumen substrata deteriorate. What this means is that possibly in another 75 years, not a single albumen print will at all resemble its original appearance. Without a monitoring program no one has any idea how rapidly further deterioration will occur. Such a monitoring program might consist of checking a statistically significant sample of albumen prints in several collections by measuring reflection densities in image and non-image areas. The densitometers should be equipped with red, green, blue and visual equivalent filters, and the same prints should be rechecked at two, five, and ten year intervals.

Another benefit from a greater understanding of the causes of highlight yellowing and overall fading would be information about the best way to store albumen prints, i.e., what are the most beneficial types of filing enclosures, framing practices, etc., in order to minimize further fading and yellowing. The reversal of yellowing that has already occurred is an extremely difficult task, principally because the silver sulfide which forms the yellow stain is much more chemically stable than the colloidal silver of the image itself. No presently known treatment can remove the highlight yellowing without completely altering the character of the print.

Generalized Image Fading

The second most prevalent kind of deterioration--and the most serious for the informational and aesthetic value of the photograph--is generalized image fading. The principal internal causes for this condition in albumen prints are the same as in other photographic materials, namely residual thiosulfate and silver-thiosulfate complexes which have been allowed to remain in the material through inadequate fixing and washing. Moreover, albumen prints are also subject to fading induced by external causes, either 1) sulfiding of the image from atmospheric sulfur compounds such as sulfur dioxide, etc., and 2) oxidation fading caused by oxidizing gases such as ozone, organic solvents, etc. Albumen prints do not respond to the so-called "bleach and redevelopment" methods which have been successful in restoring sulfided gelatin-based develop-out photographic materials. The problems with the "bleach and redevelopment" method in regard to albumen prints are that the residual silver in the highlight areas redevelops along with the image, the "redevelopment" step does not provide sufficient density overall, and finally, the color of the "restored" image is black and therefore totally out of character with the original color of the print.

Deterioration Caused by Defective Mounts and Mounting Adhesives

A third major type of deterioration afflicting albumen prints originates from poor quality mounting boards and improper mounting adhesives. These problems are serious ones because approximately 95% of all albumen prints were mounted at the time of their production. Many mounting boards used in the 19th century were composed of thin top and bottom layers of relatively good quality paper laminated to a thick core of pulp containing a high percentage of lignin. The decomposition products of lignin migrate through the top layer of the board and attack the photograph, causing staining and brittleness and accelerating and fading and yellowing of the silver image. In many cases the use of putrified starch or gelatin adhesives accomplished the same kinds of deterioration.

Other problems associated with mounts are reddish stains known as "foxing" and stains caused by mold or fungus growth. At the moment the repertoire of preservation treatments available to photographic conservators for use with albumen prints is somewhat limited; the removal of prints from obviously defective mounts and their careful remounting onto appropriate mounts with safe adhesives is the only technique for the preservation of albumen prints that has proven itself in practice. Remounting, however, does nothing to reverse the deterioration that has already occurred.

The Need for Restoration Research

The reversal of yellowing, fading and staining caused by all of the above internal and external factors continues to be beyond the present state of knowledge in the field of photographic conservation. In spite of the enormous cultural importance of the photographic record of the 19th century and the advanced state of deterioration in which many albumen prints exist today, no research into the nature of the problems or the potential for new restoration techniques has been done since the days of Haddon and Grundy.

The reasons for this lack of research may be traced to the obsolescence of albumen paper by 1900 and the attitudes which prevailed for most of the 20th century toward photographic preservation. Within 10 years of the work done by Haddon and Grundy two revolutionary changes took place in the technology of photographic printing papers. Albumen paper was replaced by somewhat similar gelatin and collodion printing-out papers in the mid 1890's, and these in turn were supplanted by gelatin developing-out papers (of the type still in use) by 1905. Naturally scientific attention turned to these materials, and the problems of albumen were forgotten. Much research has been done concerning the permanence of gelatin-based printing papers, but there is no certainty of the applicability of these results to albumen-based materials. Although the chemical and physical characteristics of albumen prints are similar in some ways to gelatin prints, there are a number of significant differences. It is now apparent that at least the restoration techniques used on gelatin prints are inappropriate for albumen prints.

The lack of organized research into the problems of albumen prints may also be explained by previously held attitudes toward the importance of 19th-century photographs. For many years the deterioration of these artifacts was ignored, and photographic copies of important images were considered by many to be a completely satisfactory substitute for the original photograph. The several new factors which in recent years have begun to change these attitudes--a new appreciation of the aesthetic dimension of 19th-century photography, a new emphasis on preservation of original photographic artifacts, and the greatly progressed decay which has beset surviving prints--now make it more imperative that some inquiries into the specific problems of albumen prints be conducted. The reward of success in such research would be that the wonderful beauty of albumen prints could be preserved for generations to come, instead of comprising an unfortunate footnote to the history of photography.