Coatings on 19th Century Paper Photographs: Guidelines for Identification

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Opleiding Conservering en Restauratie

Masterscriptie

Coatings on 19

th

Century Paper Photographs: Guidelines for

Identification

Clara Charlotte von Waldthausen Studentnummer: 10477144 Universiteit van Amsterdam, Amsterdam Scriptiebegeleider: Elizabet Nijhoff Asser Tweede beoordelaar: Dr. Arjan R. de Koomen July 2014

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I am most grateful to Lyzanne Gann for taking me on as third year intern at the former Netherlands Restoration Studios (since 2005, the Netherlands Photography Museum, Rotterdam). Through my internship with her I was introduced into the topic of coatings on 19th century paper photographs that I discuss in the research that follows.

Annette Kip, the coordinator of the Netherlands School of Conservation supported my aspiration to study a year abroad in which I thankfully was able to work closely with Barbara Brown and the Conservation and Photography staff at the Harry Ransom Humanities Research Center of the University of Texas, at Austin, Texas. Barbara Brown and Roy Flukinger made 24-hour access to the Photography Stacks and the copying machine possible. She is my role model and I am thankful for all she has taught me.

During my time in the United States I was invited to participate in the Photograph Conservation Block at the University of Delaware and I am forever grateful to Debra Hess Norris for all her support, wisdom and for sharing all that she knows in the most contagious manner. During the year abroad I was fortunate to follow the inspiring lectures on (photograph) chemistry presented by Hal Erickson, Andrew Robb and Scott Williams. They have shown me that chemistry is a truly wonderful and exciting field.

This research would not have been possible without the help of Thea van Oosten who dedicated her time to analyze FTIR spectra of almost 100 photographs and materials. Through her relations it was possible to employ the (at that time) innovative “Spectrum One” FTIR Spectrometer that was so generously loaned for the term of the research by Perkin Elmer. A warm word of thanks I would like to give to Frank Ligterink who evaluated the contents of my research and provided guidance into its organization and form. I am also thankful to Han Neevel for providing insight, and for being an inspiring teacher.

I would not have been able to perform this research if it had not been for 6 institutions that supported me by providing access to investigate their photograph collections. I am very thankful to Gerrit de Bruin, Researcher at the National Archives, Liesbeth Ruitenberg, Curator of Photographs at Huis Doorn, Professor Ingeborg Leijerzapf, former Curator of Photographs at the Print Room of the University of Leiden and also former Professor of Photography at the University of Leiden, Janneke van Dijk, Curator of Photographs at the former Royal Institute for the Tropics, Anneke Groeneveld, Curator of the former World Museum in Rotterdam and Mattie Boom, Curator of Photography at the Rijksmuseum Amsterdam.

My appreciation goes out to Jan de Vries, former Director of the Masters Program in Conservation / Restoration at the University of Amsterdam, for enabling me to re-introduce this research, and present it in a slightly tweaked manner. I am thankful also to Suzanne Maarschalkerweerd, Elizabet Nijhoff

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Asser, Arjan de Koomen, Rene Peschar and many others for their effortless guidance during the Masters Program and to the various lecturers and friends (you know who you are) that have provided food for thought and inspiration during this somewhat lengthy journey to complete my Masters.

I am lastly deeply indebted to my families (first and second) for their support in yet another study, and I am forever thankful to Hans Meesters for his guidance, friendship and insight and for truly instilling upon me the art of photography.

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1. Defining the Research Project

1.0 Introduction to the Research Project

This research is the result of an investigation performed in 1999 and 2000 into coatings on 19th Century salted paper prints and albumen photographs that was initiated during an internship at the Netherlands Photograph Conservation Studios in Rotterdam, when a number of albums with salted paper prints made by Eduard Issac Asser, came into the conservation lab for treatment.1 A few of these salted paper prints were extremely yellowed and cracking was visible in a glossy layer covering the paper photograph. (see Figure 1, Appendix I) The silver image of salted paper prints, the first photograph process on paper, is embedded into the fibers of the paper causing a matte appearance. Due to the high surface gloss of these salted paper prints it was concluded that the photographs had to have been coated and that after approximately 150 years of natural aging, the coating had yellowed.

At the time, 1997, very little research into the coating of photographs had been published. Innovative modern publications on processes and conservation such as the Salted Paper and Albumen Book (1980), written by James Riley, director of the Image Permanence Institute (IPI) in Rochester, NY, that covers many aspects of printing including permanence, mounting, finishing and burnishing makes no mention of coatings.2 The only modern publication in which information on coatings could be found was a bibliography by Susan Barger. Barger covered coatings on photographs in the 19th Century in one paragraph of the 149-page publication.3 Photograph Conservator Monique Fischer, working at the North East Documentation Center (NEDC) in Andover Massachussetts, had done preliminary work on the subject and sent this author all she had discovered while reading through old journals. This was the extent of modern research on coatings that had been performed in Europe and North America until 1999.

Intrigued by the lack of knowledge on this subject, this author decided to perform art technical source research as part of her internship at the Harry Ransom Humanities Research Center (HRC) at the University of Austin, in Austin, Texas. Photographer’s manuals, Journals of photography, art journals, chemical and technical journals in the Gernsheim Collection, and letters and journals kept by practitioners published online such as those from Henry Fox Talbot, were surveyed from 1840 until 1875 to gain insight into the use of

1_{The NFrA merged in 2006 to become the Netherlands Museum of Photography (Nederlands}

Fotomuseum) in Rotterdam.

2_{Reilly, James M. The Albumen & Salted Paper Book: The history and practice of}

photographic printing, 1840-1895. Rochester: Light Impressions Corporation. 1980. Online

website accessed May 2014:

http://albumen.conservationus.org/library/monographs/reilly/chap10.html

3_{Barger, M. Susan. Bibliography of Photographic Processes in Use Before 1880: Their}

Materials, Processing and Conservation. Rochester: Graphic Arts Research Center, Rochester Institute of Technology, 1980.

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coatings in early photography.4 The herewith-presented research followed during the final semester research project at The Netherlands Institute of Cultural Heritage (ICN) conservation training program, and has been rewritten with permission of the Exam Committee of the University of Amsterdam Conservation Program to serve as this author’s Masters thesis at the University of Amsterdam School of Conservation.5

This research project focuses solely on the coatings that were used for albumen and salted paper photographs in the 19th Century. The definition of coatings that this author has restricted both her literature and scientific research to is: any layer which is applied after processing, before or after

mounting, onto the recto or verso of a 19th century silver-based paper photograph, as part of the picture’s finishing technique or to aid in the application of color. 6

1.2 Goal of the Research

The goal of this paper is to formulate a set of guidelines for establishing the presence of a coating on 19th Century salted paper and albumen prints and evaluates these guidelines for efficacy. The questions that are investigated are: 1. Can a coating on a salted paper print or albumen print be identified

using non-destructive methods?

2. Can the main coating material be identified via these methods?

3. Can simple tools available in a general conservation lab be sufficient in identifying the presence of a coating or do analytical instruments have to be used?

1.2.1 Relevance of this Research for the Field of Photograph Conservation

Establishing the presence of coatings on photographs in general is crucial for curators and conservators for a number of reasons. The coating is a part of the photograph, and a coated surface will give unique qualities to the image. Establishing the presence of a coating is important for exhibition because depending on the materials used, the coating could degrade (for example yellow or craze) under the influence of climatic changes and / or light exposure.

For conservation, it is vital that the material nature and photographic structure of the object be established. Only then can the conservator propose a treatment

4_{http://foxtalbot.dmu.ac.uk/letters/letters.html}_{(accessed August 2014)}

5_{The ICN merged to become the Cultural Heritage Agency of the Netherlands, -}

Rijksdienst Cultureel Erfgoed, in 2006. At this time the unaccredited ICN School of Conservation was taken up to become the accredited Masters Study in Conservation and Restoration at the University of Amsterdam.

6_{Nineteenth Century photographic terminology can at times be vague. The word for}

photograph is often interchanged with words such as print, positive, picture, drawing, proof, salted paper, albumen print, enameled picture, etc.. Similarly, diverse words for coating such as encaustic, varnish, enamel, glaze, finishing layer are all used.

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that will cause minimal intervention and change in the material nature of the photograph.7_{A coating can be locally, partially or completely removed during}

mechanical, solvent or aqueous treatments such as cleaning, reduction of accretions or adhesive, tear repairs, flattening, mounting etcetera.

Removal of original material is viewed as unethical in the field of photograph conservation and the local, partial or complete removal of a coating could alter the photograph’s surface gloss and/or warrant a different aging of the photograph in that area. For instance, removal of a coating could cause fading, yellowing or silver mirroring8 of the image locally or completely. Identifying coatings can also present a clue to the working methods and techniques of the photographer and may be used to for example, support the dating of photographs

This research concentrates on salted paper prints and albumen prints because these two photograph processes were the earliest on paper and secondly because the albumen process was the most widely-used in the 19th Century. Since literature research illustrates that coatings were used from the earliest period onwards, focusing on the first two historical processes would enable a solid foundation onto which future research into the use of coatings on other photograph processes could be formed.9

1.3 Working methods and Justification of the Theoretical and

Historical Framework

Technical source research was performed initially to gain insight into working methods of photographers in the 19th Century, to gain an understanding of the coating recipes that may have been used at the time, and to attain historically true references to aid in the identification of historic coatings.10 As a result, this author composed an annotated bibliography of the various articles that mention coatings in the 19th Century literature (Appendix V.).

7_{Although a conservator’s goal is to cause minimal intervention and change, and he does}

this foremost by taking preservation measures, treatment of an object may be warranted. This author is aware that any of the above named treatments may cause unwanted change in the object, and much research in this field is needed. This is beyond the scope of this research.

8_{Silver mirroring is the visual result of oxidation of image silver producing ions that}

gradually migrate through the binder and are reduced to metallic silver on the surface of the photograph. This is visually perceived as a pearly, silver reflection on the darkest image areas.

9_{The innovative nature of this research is demonstrated by the interest of the University of}

Delaware, Metropolitan Museum, New York and the Mellon Foundation, who organized a special workshop on coatings on photographs in 2002 in which this author presented her research. During the workshop it was decided that the knowledge disseminated was so important to photograph conservation that a publication should be made. The collaboration of many professionals in the field of photograph conservation led to the joint publication, Coatings on Photographs, edited by Constance McCabe and published by the American Institute of Conservation with support from the Mellon Foundation in 2006. As a result of the research presented here, this author wrote the third Chapter.

10_{This author is aware that through natural aging, the coatings can change in their nature}

however through discussions with Thea van Oosten and Frank Ligterink from ICN, it was felt that modern reproduction coatings presented sufficient reference material.

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In the second part of the research historic recipes were selected for reproduction purposes to aid in composing identification guidelines for coatings. Seven recipes were selected from 19th Century literature, reproduced and spread onto modern albumen and salted paper prints. The recipes were selected depending on frequency of publication of the recipe in different sources and on the dangers involved with using and combining the ingredients.11 The seven reproduction coatings were firstly used to serve as reference for FTIR analysis. They were then used to understand their material composition and physical attributes and to establish the surface characteristics when applied onto photographs. It was reasoned that if such surface characteristics could be recorded, they could be used to identify coatings on historical photographs to aid in the establishment of guidelines for identification.

The third part of this research uses the knowledge learned during the first two parts (literature research and the making of historical accurate reproduction coatings) and puts the gained insight into practice. Historical salted paper and albumen prints were surveyed and one hundred photographs were selected to try and establish the presence of a coating via 4 methods of non-invasive investigation:

1. Visual investigation using ambient and raking light 2. Microscopic investigation at various magnifications

3. Ultra Violet investigation using short and long wave UV sources 4. Fourier Transform Infrared analysis (FTIR)

Used concurrently, these investigation methods were anticipated to compliment one another so that technical and visual insight into how coatings may look and how they may be perceived could be gained and to come to guidelines for identification. FTIR was added to the otherwise more practical list of methods performed in conservation labs, to determine actual coating material(s).

During the time of this research, non-destructive X-ray fluorescence and Infrared Spectroscopy had only recently come on the market. Questions as to the sensitivity of these instruments had not been answered in the field of cultural heritage and it was innovating to investigate the realms of Infrared Spectroscopy using the Perkin Elmer Spectrum One, and to test if an application for the identification of coatings could be found.

It was hoped that the first three methods, which can readily be performed by a conservator, would be sufficient for the identification of a coating, and that if material identification was necessary, FTIR analysis would provide the necessary data. Together these methods could form a non-intrusive guideline for the identification of coatings on salted paper and albumen prints.

In the pages henceforth a summary resulting from the in-depth literature research of the Western history surrounding coatings on salted paper and

11_{The 19}th_{Century photography literature is full of fires, explosions and other accidents that}

occurred in the darkroom while mixing chemicals for coatings or other photographic objectives and lab safety was a major concern during the practical work.

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albumen prints is first provided. Sources used are those found in the Gernsheim Collection at the Harry Ransom Humanities Research Center, University of Austin, Texas and most relevant sources are listed in Appendix V. Mainly English and German sources were employed but it soon became evident that the latest news and information of the time was soon to be found in photograph journals of all the major photography countries including but not limited to the Great Britain, France, Germany and the United States. The methodology of selecting and making reproduction coatings as well as the methodology used to survey historical photographs using the four methods for identification of coatings is described secondly. After the methodology of these components is introduced, the research results and discussion surrounding the reproduction coatings, survey of historic photographs and analysis of the photographs are presented.

In the final Chapter the conclusions of this research are offered and an outline of the guidelines for non-intrusive identification is presented. The appendices convey supplementary research and information gained during analyses is presented in table form. The FTIR Spectra are bundled and the lengthy annotated bibliography in Appendix V may aid the reader in performing future supplementary research.

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2. Coatings on Salted Paper and Albumen Prints from

the 19

th

Century

2.1 Coatings in the First Decade of Photography

With the invention of paper photography in 1839, the 1840’s were a period of activity and experimentation. Information on the progress and development of photography during the 40’s is mostly found in chemical and technical journals, art journals, handbooks on photography and letters and journals kept by the practitioners. Non-photography sources published major events in the evolution of photography and art journals often published articles on the philosophical views regarding the acceptance of photography as an art form in addition to exhibitions and other events in photography. Accounts regarding the technical aspects and experimentation’s performed at the time can only be found in early handbooks, letters of correspondence and to some extent in journals previously mentioned.

Evidence of experimentation amongst photographers in the 1840’s with coating salted paper prints is present in these sources but references to the recipes and their application were not found during literature research. An example of early coating use in the Netherlands is on photographs made by Eduard Isaac Asser in the collection of the Rijksmuseum. Asser coated his salted paper prints with wax and shellac.12 Although the reason of the coatings remains unclear, speculations can be made according to articles published in photographic journals in the early 1850’s when the first Photographic Journals were published. These articles mentioned that depth, brilliance and detail were gained by the application of coatings to salted paper prints because the image in uncoated prints is embedded into the paper fibers of the support.13

Due to the lack of a binder layer that separates the image from the paper support, uncoated salted paper images take on a soft matte appearance when dry. This appearance was perceived to be artistic but it had its drawbacks. The print, when wet, possessed much more brilliance, depth and details in the shadow areas than when dry. To produce these attributes in dry salted paper prints, different methods were used such as for example, coating the image or burnishing the back of the print with an agate burnisher to “harden the grain of the paper and bring out the details of the picture.”14 Rolling and heat presses were used in the earlier decades and later photographs were pressed using specially manufactured print burnishers.15

12_{According to research performed by Lyzanne Gann at the Nationaal Fotorestauratie}

Atelier (National Conservation Studios) in Rotterdam, 1998.

13_{E.G. Heineken, “Gelatinizing Positives,” Journal of the Photographic Society of London}

I, No. 14 (February 21, 1854), 163.

14_{“Positive Printing,” Orr’s Circle of Science George Gore, Marcus Sparling and John}

Scoffern, ed. (London: Houlston and Stoneman, 1856), 246-252.

photographic printing, 1840-1895. Rochester: Light Impressions Corporation. 1980.

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By the end of the 1840’s, photography groups consisting of amateur photographers and chemists had been established, and the need for the institution of a more formal body was recognized in France and England in 1851. In the same year the first Photographic Journal, La Lumière was published in France. Two years later, the Photography Society of London was inaugurated by Roger Fenton and others, and with it, the first monthly journal of photography was published in Great Britain.16 The birth of the Photographic Societies and their journals provided insight and knowledge to anyone interested in the field and created a formal circle in which observations, inventions and techniques in photography could be communicated. Other photograph journals were published later in the 1850’s and soon information was widely spread regarding for example, the latest experiments, new processes, recipes, mounting techniques and coatings.

2.2 Coatings During the Albumen Age

The albumen process was invented in 1850. The use of this process spread rapidly because the image which no longer was embedded in the paper fibers but now in an albumen binder, appeared to be more clear and sharp. There were no patent rights with this process that photographers were required to purchase and its use spread worldwide making it the most common paper process of the 19th century.17 The albumen layer created a glossy image that was viewed by many in the early decades of photography, when photographs were compared to works of art such as engravings, as vulgar.18_{To reduce the}

gloss of the albumen, coatings such as wax and encaustic pastes (a mixture of wax and other materials) were applied to the surface of albumen prints. Sometimes the albumen was mixed with substances such as starch to reduce the gloss.19

However in commercial circles as early as the 1860’s, the client posing for a photographic portrait and perhaps in some instances the photographer himself, preferred glossy photographs to matte ones as can be seen in this quote from the editor of the Photographic News, one of the most read journals of the time: “For those who follow it (photography) as a business, the case is very different, nine out of ten of our customers want their pictures to be varnished: ‘They look so much better’.”20_{And thus the trend in glossy photographs}

increased in the late 1860’s and in the 1870’s.

16_{Journal of the Photographic Society of London I, No. 1 (March 3, 1853), 1-8.}

17_{Unlike the albumen process, Henry Fox Talbot had placed a patent onto his salted paper}

process from the beginning making it difficult for any professional photographer to use it. The daguerreotype process, developed at the same time as the salted paper process carried no patent and was thus more popular and spread faster throughout the nations. Talbot lifted his patent in the early 1950’s, after the albumen process became increasingly popular.

18_{“Varnishing and Waxing Prints,” The Photographic News VI. (No. 181, February 21,}

1862), 85-86.

photographic printing, 1840-1895. Chapter 5. Rochester: Light Impressions Corporation.

1980. Online http://albumen.conservation-us.org/library/monographs/reilly/chap5.html

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During this time many commercial photographers hand-colored their photographs to make them more fashionable. Photograph surfaces that were to be hand-colored, were until the introduction of aniline dyes, prepared with surface coatings prior to color application. Base coatings such as ox gall, Gum Arabic, alum, alcohol or other ingredients were applied to the surface of albumen prints to facilitate the adhesion of the colors.21 Fresh albumen was occasionally mixed with pigments and dyes to aid in the coloring, and with oil paint, the application of a primer was recommended as an isolating layer to prevent oil from being absorbed into the paper support and causing a mottled appearance or local translucent areas in the image.22 After hand-coloring, finishing coats were applied because the refractive index of the surface is altered in areas where pigment is applied. A coating permits the print to be viewed with a smooth even surface.23 After 1864, aniline colors were introduced for hand-coloring albumen photographs and it wasn’t until later in the 19th Century that aniline colors almost entirely replaced traditional methods of hand-coloring.

2.3 The Fading Issue, Coatings and New Processes

A few years after the introduction of albumen prints, photographers began to turn their attention to the impermanence of photographs. Salted paper and albumen prints had faded and / or yellowed since the beginnings of photography only a little more than a decade earlier. Although publications on the permanence and fading of photographs are not found in the English, German or American sources prior to the institution of the Photographic Committee on Positive Printing (the Fading Committee), chosen on May 21, 1855, it is probable to assume that this topic was discussed among photographers and in letters of correspondence of the years prior to this point.24 Roger Fenton a major figure in early photography retired in 1860 due to the impermanence of photographs and many alternative processes were developed as early as 1854 when Paul Pretsch, aiming to develop a more “permanent process,” developed the Photogalvanograph that made use of ink instead of silver.25

The members of the Fading Committee were chosen by the Photographic Society of London to discover the reasons that led to the fading or yellowing

21_{“To Correspondents. A Reply from the Editor to Da Lucem,” The Photographic News I,}

No. 12 (November 26, 1858), 144. And “Tinting Photographs,” British Journal of

Photography XXII, No. 777 (March 26, 1875), 145.

22_{A Stranger, “Colouring on Albumenized Paper,” The Photographic News V, NO. 146}

(June 21, 1861), 297.

23_Ibid.

24_{Verbal communication with Saskia Asser (curator of photography), who wrote her}

Masters thesis on Nicolaas Henneman, affirmed that Henneman wrote letters of

correspondence regarding the fading of the photographs that were included into the Pencil of

Nature by W.H.. Fox Talbot.

25_{Baldwin, Gorden, Malcom Daniel and others.}_{All the Mighty World: The Photographs of} Roger Fenton, 1852-1860. New Haven: Yale University Press. 2004 pxiii

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of photographs.26 In the months following the establishment of the Fading Committee, dozens of articles were published surrounding the preservation of photographs such as on: fading, printing, treatment of residual liquids in prints, toning positive prints, chemical developing of prints, restoration of faded prints and processes for purifying papers from metallic spots. The seven members of the committee worked six months before publishing the first report in November 1855, and it contained the following four recommendations to photographers:27

1. The greatest care should be bestowed upon the washing of the prints after the use of hyposulphite of soda, and for this purpose hot water is very much better than cold.28

2. The majority of the Committee think that gold, in some form, should be used in the preparation of pictures, although every variety of tint may be obtained without it.29

3. That photographs be kept dry.

4. That trials be made of substances likely to protect the prints from air and moisture, such as caoutchouc, gutta percha, wax and the different varnishes.30

After the printing of the initial report, the search for permanency and stability continued. From 1856 and at least through the middle of the 1870’s, countless articles are found in the various Western photography journals dealing with the issues of permanence and fading.31 Throughout this time period numerous articles were also published in the same sources on various coatings that are recommended to attain permanency. Permanency was an issue all throughout the 19th Century and in 1863 the editor of The Photographic News, Wharton G. Simpson, wrote in his opening statement:

Printing without doubt still continues to be the chief photographic difficulty. Processes for the production of negatives by different methods continue to improve, and little seems left to desire in this respect; but printing still progresses with slow and uncertain steps. It is true that in skillful hands, despite the difficulties arising from imperfect knowledge and bad paper, very beautiful prints are produced. Still very little is understood of the rationale

26_{“Photographic Committee on Positive Printing,” Journal of the Photographic Society of}

London II, No. 30 (May 21, 1855), 159.

27_{The seven members of the “Fading Committee” included Philip H. Delamotte, Hugh W.}

Diamond, T. Frederick Hardwich, T.A. Malone, John Percy, Henry Pollock and George Shadbolt. Allrespected chemists / photographers and members of the Photographic Society of London.

28_{Hyposulfite of soda, or hypo as it is often coined, is the fixing chemical necessary to}

remove unexposed silver salts in the photograph after exposure. It is still commonly used as fixer today and the modern term used is sodium thiosulfate.

29_{Not all members agreed upon this point and Dr. Percy and Mr. Malone felt that there was}

not sufficient evidence in favor of gold, to warrant the recommendation of its general use.

30_{“First Report of the Committee Appointed to Take into Consideration the Question of the}

Fading of Positive Photographic Pictures on Paper,” Journal of the Photographic Society of

London II, No. 36 (November 21, 1855), 251-252.

31_{The research is limited to English and German partly because of the collection that was}

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of the process, and very little certainty exists as to the permanency of the results.32

The permanence issue is a vital factor that intertwines coating materials with photographic processes during the latter half of the 19th century. The various photographic processes of the time, and the fact that these processes are not very different to parallel published coating recipes demonstrate this. For example, Gaine’s Parchment-paper was introduced in 1857 and the Resinized Paper Process soon followed. Liesegang and Obernetter, two German scientists, developed enameled papers in 1863. Technical investigation into the fabrication of these processes as shown below, indicate that they are in fact little more than coatings applied to the paper.

Gain’s Parchment-paper announced in May 1857 and “leather varnish” or vernis cuir” are techniques that make use of salted or albumen paper or of a gelatin-coated paper that is then dipped into an acid bath. The acid bath cross links the gelatin and changes the character of the paper to “make it very strong”.33 In August of the same year, M. Blanquart Evrard’s recipe for “vernis cuir” was published in England. In Blanquart Evrard’s recipe, the only difference is that the sulfuric acid used in making Gaine’s Parchment-Paper is exchanged for tannic acid.34 In 1859, Scott Wentworth publishes his recipe for “leather varnish for positive prints”.35_{His recipe is similar to Blanquart}

Evrard however Wentworth combines the gelatin with egg white. All three techniques use similar materials and techniques, however, one is introduced as a photographic process and the others as a varnish or coating (the photograph is treated post printing and processing).

Another example of the intertwining of coatings with photographic processes is resinized paper. It was the first form of what we today call “Resin Coated (RC) or polyethylene (PE)” paper and was introduced seven years after the Fading Committee’s initial report.36 Resins such as gutta percha37 and caoutchouc (India-rubber) had been used in photography since the mid 1850’s and had been recommended by the Fading Committee as materials to be experimented with for permanence. Coating the photograph with these materials as suggested by the Fading Committee differed from Resinized paper only in that the Resinized paper was coated prior to and not after

32_{Simpson, Wharton “Opening Statement,” The Photographic News VII (1863), 2.} 33_{C.W., “Further Remarks on the Application of Mr. W.E. Gaine’s Parchment-Paper to}

Photography,” Journal of the Photographic Society of London III, No. 54 (May 21, 1857), 285-286.

34_{Blanquart Evrard, M., “New Method of Varnishing Positive Prints,” Humphrey’s Journal}

IX, No. 7 (August 1, 1857), 109.

35_{Wentworth L. Scott, “Leather Varnish for Positive Prints,” The Photographic News II,}

No. 41 (June 17, 1859), 172-173.

36_{“Resinized Paper,” Journal of the Photographic Society of London VIII, No. 125}

(September 15, 1862), 135.

37_{Gutta percha, synonymous for natural latex, was in the 1850’s also a term used for the}

first plastic material made by heating and pressing sawdust and resin together at high temperatures. Gutta Percha was introduced at the Great Exhibition of 1851 in the Crystal Palace and images of frames, mirrors, and fireplace mantels appear in the Catalogue of the Great Exhibition.

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printing.38 The manufacturer M. A. Marion, later produced a “vitrified India-rubber sheet” (1868) that served as a support for the transfer of collodion glass positive images but “could also be used as a protective coating for prints.”39 Collodion coatings also evolved into photographic processes. From the beginning of the 1850’s experimentation was performed for the transfer of glass plate collodion images onto paper, cloth, leather or other supports because the collodion image appeared to be very stable. The first article found about collodion transfers on paper was published as early as 1854.40 In 1865 in Germany, a chemist named Wothly, published a process using collodion coated enameled papers (Wothlytype process) that were uranium intensified.41 In 1865, Wharton G. Simpson introduced his the Simpsontype (collodio-chloride paper) an albumen photograph coated with collodion.42 Valentine Blanchard proposed collodion to be used as a coating for paper positives and in his address to the Photographic Society of London in 1867, he argues that collodion may be one of the best means of rendering a print permanent. Blanchard coated both recto and verso of the print.43 These photographic processes are the forerunners to the manufacture of Collodion-chloride printing-out papers that were put on the market in the mid 1880’s.

38_{Cooper, H. Jun., “The New Method of Printing. On the use of Gums or Resins Insoluble}

in Water For Positive Printing,” The Photographic News VI, No. 213, (October 3, 1862), 472-473.

39_{“Vitrified India-rubber Sheet,” The Photographic News XIII, No. 193 (May 16, 1868),}

56-58.

40_{“Collodion Positives on Paper,” Journal of the Photographic Society of London I, No. 17}

May 20, 1854), 206.

41_{“The Wothlytype” Journal of the Photographic Society of London IX, No. 150 (October}

15, 1864), 126.

42_{Mr. Simpson, “On a new Method of Printing: collodion on paper with chloride and silver}

nitrate: collodio-chloride process” The Photographic News VII, No. 155 (March 16, 1865).

43_{Blanchard, Valentine “On the Best Means of Rendering Silver Prints Permanent,” Journal}

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3. Methodology

3.1. Introduction

As mentioned in the introduction, to establish a non-destructive method for the identification of coatings on historical photographs, two types of research was performed. First, research using reproduction coatings and photographs was performed to learn the technical aspects of coating composition and application, and second, research using historical photographs was performed to examine historical photograph surfaces and to establish if visual characteristics can be used to identify coatings on photographs. Both reproduction photographs and historical photographs were inspected using four non-destructive methods of analysis including: visual analysis, microscopic analysis, ultraviolet analysis and Fourier Transform Infrared (FTIR) analysis. Combining the findings of research on the reproduction photographs and historical photographs, a non-destructive examination was performed to try to identify if photographs were coated and a guideline for identification using visual, microscopic, ultraviolet and FTIR analysis was created.

This Chapter discusses the methodology of reproduction coatings and the making of modern albumen and salted paper reproductions that could be used to apply the coating onto. Later the methodology of the surveying of historic albumen and salted paper prints, and the methodology of surveying these prints is discussed.

Seven historical coating recipes were reproduced to test the accuracy of the historic publication.44 Application of the reproduction coatings to self-made albumen and salted paper permitted the various application techniques to be studied. It was hoped that certain traces of physical manipulation and potential flaws that the coating exhibits due to its material composition or the application would be established. These traces and flaws were thought to be helpful in identifying the presence of a coating during visual analysis on the historical photographs.

By coating reproduction photographs the effects of the coating on the tone, depth and gloss of the image was studied. Finally, the photographs with reproduction coatings were used as reference material when testing the above-mentioned non-destructive methods of analysis. The reproduction coatings with known composition could also be used to build a reference library for the Spectrum One FTIR and to test the sensitivity of it. It was thought that positively identification of a reproduction coating on the modern salted and albumen prints would show that the Spectrum One was sufficiently sensitive for coating identification on historic photographs.

Six collections were visited and the surfaces of 1000 historical photographs and 22 photograph albums housing approximately 500 photographs were studied. It seems appropriate to begin analysis with visual examination because it is a form of analysis that every curator or conservator can use to survey his collection. Through the visual study of the photograph surfaces the eye becomes trained in differences in gloss, texture, and tone. These differences may provide clues to whether or not a coating has been applied to a photograph. Observed characteristics of historical photograph

44_{Some recipes published in historical sources have provided insufficient results during}

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surfaces could also be compared to the observations made on the reproduction photographs with reproduction coatings. Through the study of both the reproductions and the historical photographs a correlation between observations on both could be made and hopefully providing more clues to coating identification.

Once historical photographs had been viewed under ambient light it was necessary to examine a number of them under more ideal conditions. For this reason two albums and just over 100 photographs were loaned from three photograph collections in the Netherlands.45 The photographs were selected and notations were made as to if this author thought that the photograph was coated / possibly coated or uncoated.

Visual and microscopic analysis, ultraviolet light examination and Fourier Transform Infrared analysis were performed using 64 of the 100 historical photographs.46 If doubt remained after visual, microscopic and ultraviolet examination, it was hoped that a non-destructive form of Fourier Transform Infrared (FTIR) would provide more tangible identification. The Spectrum One FTIR kindly loaned by Perkin Elmer for this research, uses internal attenuated total reflectance to analyze the surface of materials. The machine was set up at the Netherlands Institute for Cultural Heritage (now part of The Cultural Heritage Agency of the Netherlands) and controlled by Conservation Scientist Thea van Oosten, who specializes in FTIR.

3.2 Procedure for Making Modern Albumen and Salted Paper

Reproductions

To support the research on the identification of coatings, salted paper and albumen prints were reproduced in the lab. The prints purely serve as a secondary aspect of this research. They were created to provide a physical support for the seven coatings that were reproduced from historical recipes. The recipes chosen for both photograph processes are taken from Richard Farber’s, Historical Photographic Processes. Although a modern source, Faber presents a well-researched guide with information concerning the dangers presented by each chemical used. His recipes were compared to historical recipes and found to be sufficiently accurate and the words of caution that he includes combined with the modern-day conversions of 19th Century weights and measures convinced this author to employ his guide.

Montval Aquarel Papier (cold pressed, 300g / m2_{) by Canson was chosen as the paper}

for making the salted paper prints. It is a white, rag paper which is manufactured in France by France-Papeteries Canson et Montgolfier S.A. and exhibits some similarities with historical papers used to make salted paper prints. Renaissance paper from Light Impressions was chosen as the paper support for the albumen reproductions. This paper is thin (40g / m2) like historical albumen paper and both papers were tested for silver image interaction using the Photographic Activity Test.

45_{The three institutions which provided loans were The Prentenkabinet van de Universiteit van}

Leiden (Print Collection of the University of Leiden), Tropenmuseum (the Institute for the Tropics), The Wereld Museum (The Museum of the Cultures of the World).

46_{Not all 100 photographs could be inspected in this way due to time constraints with using the}

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Similar to the widely used Rives paper in the 19th century, Renaissance paper has a watermark which can impede the image, this was cut off.47

Five cellulose acetate negatives (4 x 5 inch) and three printing frames were used for printing.48 The images were chosen for their contrast and long tonal values. A transparent gray scale was printed along with one of the five negatives.49 Three light sources were used for exposure to minimize the time needed for printing: daylight, ultraviolet fluorescent tube lighting used for sunbed tanning (brand name and other information is not available) and an ultraviolet light source manufactured by Spectroline (365 nm, model BIB-150 B/F, 220 volts, 1.0 Amps). Exposure times using the various sources lasted from two and a half hours using sunlight to 45 minutes using the Spectroline ultraviolet light source.

Processing was accomplished by rinsing each print separately in a bath with running tap water (22°C) for approximately 4 minutes. Hereafter the print was gold toned for 20 to 45 seconds depending on the freshness of the gold toning bath, fixed in two separate baths for 5 minutes each with agitation, rinsed in Hypo-clearing agent for 2 minutes and rinsed under running tap water for 20 minutes to remove residual chemistry. Tests were not performed to examine the levels of residual sodium thiosulfate. The prints were blotted between blotting paper and air-dried. At the end of each day the prints were placed between sheets of clean blotting paper and dried under glass weights. The albumen photographs were later wet mounted onto museum board according to a 19th century method using precipitated wheat starch paste, the salted paper prints remained un-matted.50

3.3 Procedure for Reproducing Seven Historical Coatings Recipes

The factors that contributed to choosing the seven recipes were: frequency of publication of a coating, date that the coating was used, ability to attain materials needed to reproduce the coating and hazards affiliated with the materials used in the recipe such as toxicity.

In selecting the seven coatings this author felt it was important to choose recipes that were published more than once and in more than one source. It was supposed that if recipes were published at various times and in various sources, their use may have been more frequent than others that were published only once. The date that each

47_{Sensitizing the salted paper prints was initially done by using a foam brush and later by floating}

to minimize abrasion of the surface fibers of the paper. Albumen papers were floated both for the albumen layer and the sensitizing solution. The sensitizing solution was applied in a darkroom under a red safety light from Kodak. Two clothes pins were affixed to the top and bottom edges of each sheet of paper to discourage curling of the paper during drying. The prints were dried in the dark.

48_{The five negatives were generously loaned to this author for the purpose of printing salted paper}

and albumen prints by Gisela van Rossum, paper conservator at the Rijksmuseum in Amsterdam.

49_{The printed tone scale can be used for eventual density metering in the future to establish image}

permanence at a later date.

50_{“Collodio-Chloride Printing Process,” Journal of the Photographic Society of London XIII, No.}

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coating first appeared in the literature was also taken into account. The earlier it appears in the literature the longer it could have been in use. The encaustic paste recipe from Adam-Solomon is a good example of this. It was published in various journals and encyclopedias for well over 25 years.51 The composition and possibility of attaining needed materials also played a role. Also, recipes that included the heating of harmful or highly reactive solvents such as chloroform were not used. As can be seen in Appendix V, the most frequently published coating materials are: wax, resins such as gum Mastic and Canada balsam, gelatin, collodion, and combinations of wax and resins such as in encaustic pastes and varnishes. For example, “white wax” was recommended for coating in eleven recipes found in Appendix V. An additional nine recipes list wax as a component for a coating. Appendix V lists 19 references to varnishes of which ten list gum Mastic alone or in combination with other resins. Gelatin is mentioned eleven times and 5 times in reference to “gelatinizing” prints through drying the gelatin coated photograph on a glass plate that is previously primed. Encaustic pastes are prepared with wax and resin and/or collodion and ten references for pastes are listed of which two are specifically named Encaustic Paste Adam Salomon and two specifically called Encaustic paste Biennert.

Due to the insight gained through literature research (Apendix V), seven coating recipes were selected:

• Gelatinizing of Positives from E.G. Heineken • Varnish for Paper Positives by H. R. Nichols • Collodion from Valentine Blanchard

• Canada Balsam • Beeswax

• Encaustic Paste M. Adam-Salomon • Encaustic Paste M. Biennert

The coatings were mixed in a lab that was fitted with a fume hood, chemical storage cabinet, and all necessary equipment.52_{This author chose to follow the original}

recipes as closely as possible and therefore did not exchange less toxic solvents for the use of the ones recommended. For instance toluene was not used to replace benzene (benzole). 53

The seven recipes that were chosen are listed below:

51_{Wall, E.J. The Dictionary of Photography for the Amateur and Professional Photographer. Eighth}

edition. (1902), 252-253.

52_{Coatings were mixed in the fume hood using glass beakers and wearing the necessary safety}

equipment: gloves, a facemask with organic compound filter, safety glasses and appropriate protective clothing.

53_{The safety material data sheets for all solvents and materials used were consulted prior to use and}

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I. Gelatinizing of Positives from E.G. Heineken 54

Water 1 ounce (31 grams)

Gelatin 1 scruple 55 (1.3 grams)

(This translates to a 4% solution of gelatin in water.) Clean glass plate

Ox gall

• Apply ox gall solution onto glass plate and protect it from dust. Allow to partially dry.

• Pour the 4% solution of gelatin onto the glass plate, allowing it to spread evenly over the plate.

• Protect it from dust and allow to dry partially.

• Test the gelatin by lightly pressing a fingertip into it. If the fingertip impression is left embedded in the gelatin, the photograph can be taken and placed image side down onto the gelatin.

• Burnish the backside of the print to remove air bubbles and allow to dry completely.

• Cut around the edges of the photograph using a pen knife. The photograph should spring off the plate with a gelatin finish.

II. Varnish for Paper Positives by H. R. Nichols 56

Gum Mastic 2 ounces

Turpentine 10 ounces

Canada Balsam 4 scruples

Since only a few prints would be coated using this mixture, this author reduced the recipe

Gum Mastic .5 ounce (14 grams)

Turpentine 2.5 ounces (71 ml)

Canada Balsam 1 scruple (1.3 grams)

• Dissolve Gum Mastic in turpentine • Add Canada Balsam

Gum Mastic was placed into a nylon stocking which was hung into the turpentine. After the Gum Mastic dissolved the impurities were contained in the stocking and did not pollute the coating solution.

• Apply an isolation layer of Gum Arabic or gelatin to the surface of the image with a brush and allow to dry.

• Apply coating using a brush.

54_{Heineken, E.G. “Gelatinizing Positives,” Journal of the Photographic Society of London I, No. 14}

(February 21, 1854), 163.

55_{Method of translating historic measurements is provided in Richard Farber’s book, Historic}

Photographic Processes, and can be found in the Appendix VI.

56_{Nichols, H.R. “A Few Words on the Manufacture of Photographic Varnishes,” The Photographic}

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III. Collodion from Valentine Blanchard 57

“Collodion mixed with a very little amount of linseed oil.”58

This author used:

Collodion (premixed) 4% solution 23 ml

Linseed oil 1 milliliter

• Apply using a brush.

IV. Canada Balsam 59

Canada Balsam Turpentine

• Allow to dissolve

• Apply an isolation layer of Gum Arabic or gelatin using a brush to the image and allow to dry.

• Apply coating using a brush.

V. Beeswax 60

Beeswax 2 ounces (33.5

grams)

Turpentine 2 ounces (33.5

grams)

• Melt the beeswax “au bain Marie” and slowly add turpentine

• Apply with a soft flannel cloth in three areas and spread. Wipe off excess and polish using fresh cloth.

VI. Encaustic Paste M. Adam-Salomon / H.P. Robinson 61

Pure virgin beeswax 500 grams

Gum Elemi 10 grams

Benzole (Benzene) 200 grams

Essence of Lavender 300 grams

Oil of Spike 15 grams62

(This author used 1/15 of the recipe)

• Dissolve Gum Elemi in benzole (benzene), essence of Lavender, and (oil of spike) • Melt wax au Bain Marie

• Mix wax with other ingredients

• Heat mixture until wax is evenly distributed throughout mixture.

57_{Blanchard, Valentine “On the Best Means of Rendering Silver Prints Permanent,” Journal of the}

Photographic Society of London XII, No. 181 (May 16, 1867), 38-40.

58_Ibid

59_{“First Report from the Fading Committee,” Journal of the Photographic Society of London II, No.}

36 (November 21, 1855), 251-252.

60_{“On the Preservation of Photographic Pictures. To the Editor of the Photographic Journal,”}

Journal of the Photographic Society of London III, No. 41 (April 21, 1856), 35.

61_{“Encaustic Pastes--M. Adam-Salomon’s Formula,” The Photographic News XII, No. 523}

(September 11, 1868), 433-434.

62_{Since oil of Spike could not be located it was replaced with essence of Lavender for the}

reproduction of this coating. Oil of Spike appears to be similar to essence of Lavender, and the two are used interchangeably in art supply stores.

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• Apply with a soft flannel cloth in three areas and spread. Wipe off excess and polish using fresh cloth.

VII. Encaustic Paste M. Biennert 63

White wax 11 grams

Ether 32 grams

Plain Collodion 24 grams

White Shellac 16 grams

Alcohol (Ethanol) 8 grams

• Dissolve shellac in alcohol (Ethanol) • Melt beeswax au Bain Marie

• Mix the ether with collodion • Mix all three mixtures together

• Apply with a soft flannel cloth spread. Wipe off excess and polish using fresh cloth.

The coating was later thinned with 16 milliliters of ether and 6 milliliters of ethanol.

3.4 Procedure for the Application of the Seven Reproduction

Coatings onto Modern Salted Paper and Albumen Prints

Since tonal values and densities of the modern albumen and salted paper prints varied due to differences in the light sources and exposure time during printing, it was decided to coat only the left half of each reproduction photograph. This provided for easier comparison between coated and uncoated regions and the effect that a coating had on the specific photograph. In all cases except the recipe by E.G. Heineken 4 or 5 prints were treated: two salted paper prints were coated with each coating and two albumen prints. Five prints (an additional albumen print) were coated with the beeswax and Gum Mastic coatings. The recipe by E.G. Heineken is recommended for salted paper prints and 10 salted paper prints were used in an effort to reproduce the coating.

All coatings except the one by E.G. Heineken were applied using a flannel cloth if the consistency was paste, or a one inch wide brush made from soft sable hair, if the solution was fluid. The cloth was dipped into the paste, applied in three areas, and rubbed into the image of the photograph. Excess paste was later removed with a clean cloth and the photograph surface was buffed to achieve the results described in each recipe. For fluid solutions, the brush was dipped into the solution and drawn evenly, from top to bottom of the surface of the image. To coat one half of the photograph it was necessary to make at least three draws with the brush to achieve an even coat. Gum Mastic and Canada Balsam coatings were applied after one of two grounding layers, a 3% gelatin solution and a Gum Arabic solution, was applied onto the photographs. These grounding layers protect the photographs from absorption of the coating into the photograph support. The applied coatings were allowed to dry and the photographs were pressed for one week.

63_{“Biennert, M. “Foreign Miscellanea,” Journal of the Photographic Society of London XIII, No.}

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3.4.1 Gelatinizing Positives by E.G. Heineken (see Figures 9 & 10)

Photographs were cut in half so that one half was left uncoated and could be used to compare with the results of the coating. Ten attempts were made to apply a glossy gelatin coat to the surface of albumen and salted paper prints:

• Two attempts using a 4% solution and the recipe as directed.

• Two attempts using an 8% solution, which was listed as an option in the recipe. • One attempt was made using two coatings of ox gall.

• One attempt replacing ox gall with melted wax.

• One attempt replacing ox gall with a solution of wax dissolved in turpentine. • One attempt using a more concentrated solution (30% more concentrated than

original) of ox gall.64

• One attempt replacing the glass plate with thin, clear polyester film (Melinex) and using an 8% solution of gelatin.

• One attempt replacing the glass plate with heavy Melinex® and using a 6% solution of gelatin. A glass plate was used as weight to avoid lifting and warping of the photograph during drying.

3.4.2 Pastes (see Figures 11 – 20)

The beeswax paste was applied using a cotton rag. Prior to coating the second photograph, the paste was diluted using 20 milliliters of turpentine, reheated and cooled. The much softer solution was spread more easily across the remaining salted paper and albumen prints and then buffed. The encaustic paste from M. Adam-Solomon was applied onto the four prints in the same fashion as the beeswax. The encaustic paste was not diluted. The encaustic paste Biennert was applied to one of the salted paper prints. It was diluted with 16 milliliters ether and 6 milliliters ethanol before applying it to the remaining prints.

3.4.3 Fluid Coatings (see Figures 21 – 30)

Three salted paper and two albumen prints were coated using the Varnish for Paper Positives. A grounding layer of gelatin was applied to one albumen and one salted paper print and a grounding layer of Gum Arabic was applied to the remaining salted paper and albumen print. Once the grounding coat was dry the “varnish” was applied using a brush. The grounding layers were applied in the same fashion prior to application of the Canada Balsam in turpentine coating.

Four prints were coated with the collodion coating. Initially a 4% solution of collodion was drawn across one of the salted paper prints. Before applying the collodion evenly to one of the two albumen prints, the collodion was thinned with two milliliters of both ether and ethanol to the collodion. The remaining albumen and salted paper prints were coated after two more milliliters of ether and ethanol had been added to facilitate application.

64_{This was accomplished by allowing the original solution to vaporize and weighing the ox gall until}

Coatings on 19th Century Paper Photographs: Guidelines for Identification

Masterscriptie

Coatings on 19

Century Paper Photographs: Guidelines for

Identification

Contents

Acknowledgements

(5)

1. Defining the Research Project

(7)

2. Coatings on Salted Paper and Albumen Prints from the 19

Century (12)

3. Methodology (118)

4. Research Results and Discussion (33)

5. Conclusion (55)

Bibliography

(59)

English Summary (61)

Dutch Summary (62)

Appendix

Acknowledgements

1. Defining the Research Project

1.0 Introduction to the Research Project

1.2 Goal of the Research

1.3 Working methods and Justification of the Theoretical and

Historical Framework

2. Coatings on Salted Paper and Albumen Prints from

the 19

Century

2.1 Coatings in the First Decade of Photography

2.2 Coatings During the Albumen Age

2.3 The Fading Issue, Coatings and New Processes

3. Methodology

3.1. Introduction

3.2 Procedure for Making Modern Albumen and Salted Paper

Reproductions

3.3 Procedure for Reproducing Seven Historical Coatings Recipes

3.4 Procedure for the Application of the Seven Reproduction

Coatings onto Modern Salted Paper and Albumen Prints