Professional Development: Chemistry for Conservators

J.M.Iacchei

Each year I am given the opportunity to pursue professional development relevant to my position in Conservation. This support for continued growth is an invaluable benefit. This year, I decided to start working on one of my most challenging obstacles in Conservation (and Academia): Chemistry.

It is easy to get lost in the daily work – surface cleaning, stabilization, humidification, etc. that are familiar and routine – and lose sight of the underlying chemical principles that are ever present in our treatment decision making. I felt that getting a grasp of these principles was essential to my professional growth. I wanted to better understand why I was carrying out treatments and be able to apply that understanding to decision-making of items and materials that were not familiar and treatments that were not routine.

With Chemistry being well beyond my comfort zone, diving into a college level Chemistry, 18 years after my last Chemistry course, was a little too ambitious. Instead, I chose to apply to the Chemistry for Conservators correspondence course offered through International Academic Projects.  It is designed for those of us who do not have a strong background in Chemistry, but who work closely with it every day.

The course distilled Chemistry down to the fundamental principles that directly impact conservation practices – and it took out “the math”.  It is divided into four blocks to be completed over 4 months, each block building upon the last as new topics are introduced. Block 1 introduced the physical world with focus on air and water; Block 2 covered basic chemical principles – atoms, electrons, compounds, reactions, molecular models; Block 3 began to link the principles introduced in Blocks 1 and 2 to deeper concepts – solutions, electrochemical principles, organic compounds, polymers; and Block 4 addressed the challenges conservators are presented with most often – the effects of water, cleaning –why, when, and how much; adhesives, and degradation. Each of these 4 Blocks was accompanied by readings from the textbook (Chemistry 2nd ed.), the Science for Conservators Series, Volumes 1-3, and supplemental course notes accompanying each block, as well as experiments (materials supplied) and review questions. The textbook provided a general introduction to the topics covered, the Science for Conservator Series and course notes provided a more technical explanation, the questions highlighted key concept, and the experiments provided a concrete visual example of the concepts discussed in the texts.

Though simple, I found the experiments required the most time and independent thought. They provided a means to practice those skills needed in conservation assessment and decision making: observation, organization of thought, ability to draw conclusions, and direct application of understanding gained from drawn conclusions.

This course was challenging, but manageable. It is noted that is a time intensive course and to plan for 10-12 hours/week to devote to the material. This is fairly accurate – less if you are a quick reader, and Chemistry comes naturally to you; more if you are a slow reader, like to take meticulous notes, need to re-read, and Chemistry is not you forte. The course covered topics across conservation – extending beyond the conditions found with paper and photographic collections with which I am most familiar. Metal, ceramic, glass, and textile materials, have been surfacing more and more often in the conservation lab from Cornell University Library Collections. Having some framework and resources will be helpful in understanding current conditions and guiding treatment needs. With this course, I am better equipped to take a more informed approach to the treatment of the materials I am responsible for preserving. And while there is more to learn, I left this course with a foundation to build upon. I gained greater awareness of the underlying chemical principles that explain current conditions and the potential options and outcomes of material choices and treatment methods.

Here are two examples:

Shown here is a tintype (silver image on black lacquered iron support) from the Loewentheil Family Photographic Collection in the Library’s Division of Rare and Manuscript Collections. It demonstrates how corrosion can occur if the tintype is exposed to poor environmental conditions. Rust is the slow oxidation of iron. It occurs as 2-part reaction when the iron support is exposed to BOTH air and water. First the iron is oxidized by the air to form iron oxide. The iron oxide then reacts with moisture in the air to produce hydrated iron oxide-more commonly known as rust. By minimizing one of the two factors causing rust to occur- exposure to air or water/moisture in the air- you can assist their preservation.

Late 19th and early 20th century newspapers provide excellent examples of cellulose deterioration caused by acid hydrolysis. Cellulose in a polymer of glucose which forms from condensation reactions that occur between the reactive -OH (hydroxyl) side groups.

One of the ways these cellulose chains are broken down is by acid hydrolysis. In the presence of moisture, acids from the environment (air pollution or poor quality enclosures) or from within the paper (raw materials, manufacturing processes) repeatedly cut the glucose chains into shorter lengths. This reaction also produces more acids – providing fuel for further reactions and continued degradation. This newspaper shows the affects of this deterioration–brittleness, loss of strength, crumbly edges, and darkening.  This course provided me with an excellent background to navigate the variety of approaches to mitigating these concerns–treatment, environment, and enclosures.

I am grateful to Cornell University Library, Tre Berney, Director Digitization and Conservation Services and Michele Hamill, Paper and Photograph Conservator, for their continued support and encouragement of my professional development, and the rather generous amount of time I was given to spend on this coursework.

 

Pigmeat’s Laugh Hepcats

Jill Iacchei and Michele Hamill

Cornell University Library features a growing number of archives documenting contemporary, musically based cultures such as punk, Hip Hop, black metal, and Latin salsa. Working in the Conservation Lab, I have had the privilege of working with many of these collections, which often contain a fascinating mix of photographs, flyers, artwork, and LPs. A recent addition is the poster shown below promoting the 1947 film short “Pigmeat’s Laugh Hepcats” starring Dewy ‘Pigmeat’ Markham (1904-1981).

Before treatment

This poster recently arrived in Cornell Library’s Division of Rare and Manuscript Collections (RMC) as part of their efforts to document 20th century music and culture. It advertises a 1947 film featuring Pigmeat Markam, whose popular 1968 single “Here Comes the Judge” is frequently cited as a precursor to Hip Hop.

Before arriving at CUL, the poster had been folded multiple times, resulting in deep folds, some splitting and torn.  Rubber-based and acrylic pressure sensitive tapes had been used to reinforce these areas that had split or torn. Tape may go on clear at first, but deteriorated rubber-based tapes stain the paper a disfiguring amber color.  The edges of the poster had many small losses and tears and the lower right corner was fully detached. Overall, the poster had yellowed in appearance and had some surface dirt.

Left: discoloration and staining resulting from tape deterioration. Right: Edge tears and losses.

The poster was brought to the Conservation Lab to fill and stabilize the numerous edge tears and losses, reduce the dark staining caused by rubber-based tape residue, to slow deterioration of the support with aqueous treatment, and to be housed in a way that would offer support, prevent further damage, and facilitate access.

The poster was first surface cleaned with smooth sponges to reduce dirt—this step is necessary before any aqueous or chemical treatment so surface dirt isn’t trapped in the paper support. The plastic carriers of the tape were removed and adhesive residue was reduced mechanically. Discreet testing of the inks and paper support was then performed to determine what aqueous or chemical treatments may be possible.  Testing showed the red and black lithograph printing inks were stable in water and that the paper support would absorb water readily, indicating that the poster would respond well to aqueous treatment. Testing also indicated that the tape adhesive residue and staining could be solubilized and reduced from the paper support using a polar organic solvent.

Stain reduction in process

Shown above is this stain reduction in process to a corner that had separated from the remainder of the paper support. Areas of the poster with adhesive staining were placed on the suction table and masked off. The solvent was painted over these areas so the residue and staining would be pulled through the poster support onto the absorbent blotter below, thereby reducing the residue and associated discoloration. This improves the paper condition and brings your eye back to the poster design and away from condition concerns.

Next, the poster was treated aqueously to remove soluble degradation products within the support, in effect slowing further embrittlement and discoloration that these degradation products cause. The drying and flattening of the poster after the aqueous treatment reduced the deep folds, giving the poster back some of its intended original appearance—a smooth surface that showcases the striking design.  The areas of loss and tears were stabilized with Japanese tissue toned to blend with the support, unifying the appearance of the poster. A polyester sleeve allows the poster to be stored and handled safely and securely.

Aqueous treatment removes soluble degradation products within the support.

Poster treatments can run the gamut of basic stabilization to more complex treatments such as this one, depending on condition, use, and importance.  After treatment, this poster now joins the rest of RMC’s deep and growing collections documenting 20th century music and culture.

After treatment

You can listen to Markham’s Here Comes the Judge here.

 

 

How to cut off your head and lay it on a platter.

Don’t Lose Your Head!

by Michele Brown

An oldie, but goodie: “to cut off one’s head, and to laie it in a platter, which the iugglers call the decollation of Iohn Baptist” from The discouerie of withcraft [The discovery of witchcraft] by Reginald Scott. This wonderful work argues against the existence of witchcraft and includes descriptions of popular jugglers’ tricks. Look for the 1665 edition in the “ Skeptics and Dissenters ” case in the Witchcraft exhibit now in the Hirshland Gallery of the Carl A. Kroch Library. Cornell’s Witchcraft Collection also includes a copy of the 1584 edition.

Produced by different printers 80 years apart, there are interesting variations in the illustrations of these 2 editions.

Reginald Scott, 1584.

To cut off ones head, and to laie it in a platter, 1584

Reginald Scott, 1665.

To cut off ones Head, and to Lay it in a platter, 1665.

 

 

 

 

 

 

 

 

 

 

The typography of the the title pages is also very dissimilar.

Title page, 1584.

 

 

Title page, 1665.

The 1584 edition is notably smaller. It appears to have been severely chopped–possibly during the rebinding process. It’s unlikely that the current binding is its first.

Our curators prefer minimal intervention and have asked us to retain evidence of previous repairs and other signs of use. These 2 volumes  provided different treatment challenges.

The 1584 edition came into the lab in 2016. It had been rebacked with calfskin at some point in its history, and this repair was showing signs of fragility. The inner joints were cracked, the head and tail caps were worn, 2 corners were worn, and there were losses on the spine, but the boards were still attached. The repair was still doing its job, but needed to be revitalized.

 

1584. Front, inner joint, before treatment.

1584. Front board, before treatment.

 

 

 

 

 

 

 

 

 

 

1584. Spine before treatment.

The 1665 edition came into the lab because it was selected for the current Witchcraft exhibit. At some point, it  had been rebacked with sheepskin. What appears to be the original spine label had been retained. New endsheets had been added and pasted over the original pastedowns–probably as part of the repair. The outer and  inner joints were broken and the boards were detached. The sheepskin spine was dessicated and its top layer was peeling off. This repair was no longer effective.

1665. Front board, before treatment.

 

 

1665.  Front inner joint, before treatment.

 

 

 

 

1665. Spine, before treatment.

In both cases, we retained evidence of the previous repairs, but the 1665 edition required more intervention.

Treatment of the 1584 edition:

We filled losses and reinforced the weak inner joints using various Japanese tissues applied with wheat starch paste. The loss on the spine was repaired with layers of Kitikata and pure kozo Moriki tissue; the headcap and 2 board corners were reinforced with Moriki, and the inner joints were covered with Sekishu. Essentially, we repaired the repairs.

 

1584. Front, after treatment.

1584.  Front inner joint, after treatment.

1584. Spine, after treatment.

Treatment of the 1665 edition:

Since the boards  were detached, we opted to reback this volume with leather. We chose fair goatskin from J. Hewit because that leather is of good quality and  looks similar to sheepskin. We repaired the “new” endpapers. The spine from the previous repair was too deteriorated to use (that would have been preferred), but we retained the spine label and added blind tooling to mimic the previous rebacking.

If a leather binding needs to be completely rebacked, we will generally use leather as the repair material. To facilitate reversibility, we line the spine with Japanese or Korean tissue using wheat starch paste before adding a lining of unbleached cotton.  Strength is added to the joints by extending this cotton lining onto the boards.

Our protocol for leather rebacking is quite similar to that described in James Reid-Cunningham’s  workshop in leather rebacking at the Guild of Book Workers 2013 Standards of Excellence.

1665. Front inner joint, after treatment.

1665.  Front, after treatment.

1665. Spine, after treatment.

There was a time when we might have tried to remove the earlier repairs before adding our newer, “better” treatments. Now, as we focus on maintaining the history of use of our collections, we retain these repairs and work around them.

Descriptions of the “decollation of John Baptist” and other tricks (“thrust a bodkin into your Head, and through your Tongue &c.”) are in Book XIII, Chapter XXXIV. Both editions of The Discovery of Witchcraft, may be viewed  through Early English Books Online via the Cornell catalog.

 

 

 

 

Workshop Summary: The Use and Creation of Pre-Coated Repair Materials

Michele Hamill

Increasingly in libraries and archives conservation there is a need for practical, safe, and efficient repair materials that address diverse collections and priorities, and can be used by a variety of practitioners (conservation staff, interns, and supervised students and volunteers). Pre-coated repair materials can fill some of this need with their versatility, convenience, and ease of use.   Pre-coated repair materials (usually Japanese tissue coated with an adhesive and then dried) supplement traditional conservation mending techniques like wet wheat starch paste applied to tissue.  At the point of use, the adhesive on the pre-coated tissue is reactivated with water, solvent, a combination of water and solvent, or heat.  A low amount of water, or no water at all, make them very useful in a variety of treatment scenarios with sensitive media, coated papers, easily stained papers, and in prepping collections for digitization, in production projects, and off-site work.  There is time and effort in preparing the pre-coated tissues, but once made, they can last a long time which adds to their convenience.

The conservation community is highly interested in these pre-coated materials and how they may benefit their collections, as evidenced by the over 150 conservators, technicians, and students who have taken this workshop.  I was interested to learn how these pre-coated materials may be used with Cornell Library’s paper and photograph collections, particularly modern archives collections (often with brittle paper and modern media), iron gall ink documents, architectural drawings, newspapers, and resin-coated photographs.  The workshop was a great learning experience which increased my knowledge and familiarity with these repair materials and techniques.

The beautiful Indiana Historical Society served as host for this recent workshop on the use and creation of pre-coated repair materials, sponsored by FAIC.

The workshop was organized by IHS book conservator Kathy Lechuga, with assistance during the workshop by IHS conservators Stephanie Gowler and Ramona Duncan-Hines. The IHS conservators did an outstanding job preparing the vast amount of materials for the workshop and generously opening their lab for our use.

The IHS was a fantastic site for a workshop with convenient lecture facilities and their wonderfully outfitted conservation lab, large enough to accommodate 18 conservators working there over 3 days.

The workshop instructor, Sarah Reidell, Head of Conservation at University of Pennsylvania Libraries, has deep expertise in the subject of pre-coated repair materials and her website is a great resource with a bibliography and photo galleries of previous workshops.  Sarah was an outstanding instructor, knowledgeable, enthusiastic, and encouraging.  Encouragement played a key role in the workshop as the techniques and materials involved were many, and skill levels and prior experience were diverse.  Using a combination of informative lectures, instructor-led demonstrations, and group discussions, Sarah presented information on a variety of adhesives and techniques to apply them successfully to tissue, and then how to reactivate the pre-coated tissue for use on a wide variety of collection materials.

Sarah is shown here demonstrating preparing pre-coated tissue using a mix of wheat starch paste and methyl cellulose.

One of the best parts of the workshop was being guided by Sarah to experiment, critique, engage with other participants, and move outside your usual pattern when approaching repair, in a supportive, collegial environment.

The advantages of pre-coated repair materials are many and include versatility, increased choice (type of paper, adhesive, reactivation method), more control, customization, ease, speed, portability, consistency, and production.  Disadvantages can include “hand” (your skill level) in making and using the tissues, possible solvent sensitivity of conservator and object, and inadequate reactivation which could lead to adhesive failure.  Through the workshop, we learned many techniques for applying the adhesive(s) onto very thin Japanese paper and reactivation methods to optimize adhesion success.

The first afternoon of the workshop was spent making tissues with starch and cellulose ether adhesives.  These are easier to make than the acrylics so we were able to hone our application techniques (drop, brush, screen) and application direction (left to right, Union Jack) and then adding the tissue (top edge laid down first, or bias drop—my favorite), or applying the adhesive directly to the tissue (Tricky! A light hand and mindfulness help a lot).  For me, applying a layer of adhesive to the polyester and then dropping the tissue onto the adhesive created a nice adhesive layer, without roughing up the paper fibers which can happen with the brush-through method. We experimented with applying the adhesives to the polyester support in a variety of ways (Hake or synthetic brushes (easier to clean!), rollers, foam brushes, and stipple brushes).  Helpful tips include humidifying thicker papers in advance and adding a spritz of water to the applied adhesive layer to encourage capillary action.  But resist the urge to “fix” the tissue (a strong inclination in a conservator!) once it is down.  Practice and patience are key.

Sarah is seen here showing the “top edge down first” method of dropping very thin Japanese tissue onto adhesive. Her preference (and mine as I practiced) is to drop the tissue on the bias, center first.

The adhesives covered in the workshop included wheat starch paste (the staple adhesive of many conservation labs), cellulose ethers (like methyl cellulose), proteins (including gelatin and isinglass) and synthetic adhesives (including those used to prepare your own heat-set tissues). Great tip: Soak wheat starch paste in water (in whatever proportion your lab uses) for 20 minutes prior to cooking. This soaking promotes swelling of the starch granules which makes for a shorter cook time (since they are already swelled) and a velvety smooth paste.

Included in the outstanding workshop handouts were detailed descriptions of the adhesives (shown here taped to the wall near the adhesive) noting concentration, common preparation, application and reactivation methods.

The application techniques included drop, brush, foaming, screen, and squeegee. The self-leveling effects of paste and cellulose ethers eased many a tissue that was a bit wrinkled during application but dried into useful sheets. Here, Sarah is foaming adhesive with a stiff brush through a screen to create a light adhesive layer.

Throughout the workshop Sarah created visual and descriptive summaries of observations and critiques. The “vertical tideline” illustrated how water evaporates from the coated tissue, creating the adhesive film layer.

The practical information shared during the workshop was really helpful—like keeping dedicated brushes for this purpose; prewetting brushes to aid cleanup; preparing the tissues over a darker surface (like Kraft paper) helps visibility during the coating; which polyester (regular or silicone coated) would allow the prepared tissue to release (hint: use silicone release polyester for the acrylics OR peel them off of regular polyester when almost dry, otherwise they will be stuck); tips to avoid contaminating adhesive stock (chop clean mat board scraps into disposable sticks or get a cheap bag of craft sticks); labeling techniques (the future usefulness of the pre-coated papers depends on good labeling including date, adhesive, concentration, and paper type, and application technique); move and dry the newly made tissues flat (or the adhesive will pool down to one edge); smaller sheets are easier to make (yes, yes, they are!); and how to store the prepared tissue (use the creation polyester as a support for thin tissues; and label folders by adhesive and paper type).

The second day of the workshop was spent working with the acrylic adhesives.  The advantage of acrylic adhesives is they can be reactivated with solvent or heat.  Concern of heat applied to collection materials is mitigated by keeping the temperature controlled with a rheostat and using small tips (no home irons here!) on the tool to deliver the necessary activation heat over only the affected area, limiting heat exposure to the surrounding area.  Weighting the treated area allows the reheated adhesive to cool and become solid which helps secure the mend. My comfort zone is very much in starch, protein, and cellulose ether adhesives so I really valued this opportunity to work with a variety of synthetic adhesives.  Sarah’s bibliography (on her website) includes some great articles describing synthetic adhesives. While there are some commercially available heat set tissues, there is a distinct advantage to creating your own tissue which allows for full control over the type of adhesive, type and weight of paper, and tone.

Pre-coated repair materials can be prepared on a variety of weights of Japanese tissue.  Very thin Japanese tissue (like tengujo, Berlin tissue, or RK-00) have the advantage of translucency so text or image is still visible through the repair. For convenience in the workshop we used untoned Tengujo tissue (5 g/m2) but the tissue can be toned with acrylics in advance to better match the item being treated.  The thinness of the tissue helps mitigate one of the disadvantages of pre-coated materials –that you can’t tear a feathered edge but instead have to cut, score, or prick the tissue.  Thin tissues don’t have the undesirable hard edge of straight-cut, thicker repair tissue and are visually unobtrusive.

The white tengujo tissue is visible on this example but would be less obvious if toned.

The needs of the object to be stabilized determine which pre-coated tissue may work.  There is no one solution to fit every problem.  Instead the workshop gave us options that could be part of the solution while factoring the extent and degree of conservation concerns; the object’s reaction to water, solvent, or heat; the surface (texture, gloss) of the object; and need of the object to flex, fold or move.  The usual steps that may be needed for preparing an item for mending, like surface cleaning, and humidification and flattening, hold for pre-coated repair materials as well.  Surface dirt in particular could present a barrier to adhesion.

The third day of the workshop was dedicated to reactivation methods on a variety of sample collection materials—coated paper, brittle paper, newspaper, tracing paper, and photographs.  We were encouraged to create tears and add problematic media like marker and ball point pen.  Straight tears (whose edges align) respond well to pre-coated repair materials.  Scarfed tears (where the edges overlap) may need reinforcement on both sides or additional adhesive fed into the overlap areas. I had some great success with a heat-set adhesive mix used at NARA on several of the practice samples.

The IHS generously donated deaccessioned envelopes with iron gall ink (which has water sensitivity and so is an ideal candidate for pre-coated repair tissue) as practice samples. There were also lots of lignin-containing papers, waxy tracing papers, coated paper, parchment, and photographs to experiment with.

I left the workshop excited about the possibilities for using pre-coated repair materials for the paper and photograph collections at Cornell Library.  So far, we’ve prepped toned pre-coated repair tissue for a large collection of iron gall ink documents and a newspaper project.  Thanks to Sarah, Kathy, Stephanie, Ramona, and all the workshop participants for a great experience.

 

 

Conservators in Action

Michele HamillDuring a recent visit to the beautiful conservation lab of the Indiana Historical Society (IHS) for a workshop on pre-coated repair materials, we had the opportunity to tour their History Lab .  The History Lab is dedicated to advancing the public’s knowledge about conservation and preservation.Be still my conservator’s heart!  An entire exhibit space and teaching facility encouraging the exploration of how IHS collections are preserved, what visitors of all ages can do to extend the life of their family collections, and learn about the different processes involved in making photographs, books, and paper artifacts.

An engaging and fun interactive display lets visitors explore a variety of artifacts and manufacturing processes in depth.

The components of this cased photograph, a tintype (a unique photographic image on a lacquered iron base), are displayed to illustrate the complex, composite nature these artifacts.

The History Lab offers a view of the state-of-the-art IHS conservation lab where visitors can see conservation in action; hands-on activities, like stabilizing paper documents; and many displays –good vs. bad paper; a recent conservation treatment, and a touchable array of materials used to make artifacts.

The visible effect of all that touching is striking. The white sheet on the far right– with the hole –is paper!

The touch display is paired with an explanation about why conservators don’t generally wear gloves during treatment. Gloves make sense in some reading room situations and with some types of vulnerable collection materials.

A detailed explanation of this conservation project was accompanied by water samples showing the discolored, acidic, degradation products that are released during careful aqueous treatment.

An impressive display illustrating how enclosures impact collection materials.

The “Unfortunate Mr. Foster” helps to illustrate how to avoid damage in home collections.

On the left is the instruction space in the History Lab for walk-in visitors, groups, and families to learn about paper conservation stabilization techniques. On the right, is the larger teaching space where the IHS hosts students from colleges and high schools, volunteers, and members from surrounding cultural institutions. The IHS store also sells archival storage boxes and basic mending kits (with instructions) to promote care of collections to its visitors.

The tools and technology used in conservation are also evident in the History Lab—on the left is a view of the IHS conservation lab and, on the right, the digital microscope exploration station showing a detail of the red watercolor used in the flower illustration.

The History Lab is welcoming, engaging, and instructive. What a wonderful way to promote how conservation benefits collections, and as a powerful teaching tool about the material culture in our everyday lives. It was also a good prompt to share what we do here at Cornell so stay tuned for a recap on the pre-coated repair materials workshop held at IHS and how we may use those techniques on our collections, and a fascinating look at squeezes (paper cast impressions) from the Parthenon.  Conservators in action!

 

 

“Less of You; More of My Ancestors” | Part II

J.M. Iacchei

In Part I of this blog series I introduced barkcloth, gave a brief historical and cultural overview, described methods of production, and concluded with the importance of conservation and preservation efforts. Part II continues with highlights from the treatment of the 12 pieces of barkcloth from the Cornell Costume and Textile Collection.“Less of you; more of my ancestors.” These were the words of guidance shared by a colleague when I inquired about treatment for this collection. I wanted to be certain that an appropriate level of treatment was provided without compromising the historic integrity of these ethnographic items. Because many of these pieces of cloth were oversized, they would need to be rolled both for final storage, and for transport to and from the digitization studio. This would mean needing the strength to withstand numerous rollings and unrollings during the imaging process, as well as afterwards in use in instruction and research.

In addition to this stability concern were the inherent causes of deterioration rooted in the items’ history, extending from the time of manufacture and the processes involved to use, and the environmental conditions of previous and present storage.

Before discussing the causes of deterioration, it is worth noting that some parts of the manufacturing process actually inherently strengthened the quality of the cloth produced. Steps taken during the pre-beating processes, and the nature of the beating and drying processes each involve aspects that facilitate the longevity of the cloth.The practice of soaking or steeping the bark for several hours prior to beating encourages a stronger and more flexible cloth. As a result of this process, bacteria and fungi from fermentation cause the plant cell wall material to break down, allowing the pectin and hemicelluloses that normally stabilize the cell walls of the living plant to solubilize and redistribute. Because of this redistribution, the resulting cloth is more flexible. The pectin and hemicelluloses that remain in place add strength to the fibers and consequently, also to the cloth.[1]

During beating, the grooves on the face of the beater spread the fibers and alter their parallel orientation to one that is angled and interlocking as well as allow excess water and air to escape. This interlocking, rather than parallel orientation, is stronger and less prone to lateral tears that most often occur parallel to the grain of the cloth’s fiber.[2] In the drying process, the barkcloth is stretched out in the sun. The high UV content of the tropical sun stunts the growth of micro-organisms.[3]

It is the following stages of decoration, use, and storage conditions that most contribute to deterioration. Just as environmental factors affect paper materials, mechanical stresses, light exposure, fluctuations in relative humidity, biological agents, and pollutants each contribute to further deterioration of barkcloth; the effects of which can be seen in color changes, staining, insect damage, mold growth and weakening of fibers.

The traditional methods of island storage were not preservation-minded. Typically, large pieces of barkcloth were stored in rolls among the rafters of the home, often in areas affected by cooking smoke. While the cooking fire kept the cloth dry and free of mold and the aldehydes in the wood smoke acted as a preservative against bio-deterioration, the exposure to smoke allowed for the collection of soot, an environmental pollutant which will overtime lead to deterioration.[4]

The dyes, pigments, resins, gums, paints, and oils used to decorate and finish barkcloth over time can deteriorate – becoming faded, brittle, and flaking.  Consequently, the cloth below the colored area will also become brittle and stiff, causing breaking, tearing along folds, or separating along the grain, leaving holes.[5]

In this collection, the main concerns were the stubborn folds incurred from previous storage, and the embrittlement of  the dyes used to apply designs to the cloth.

Eleven of the twelve items were stored together over long periods of time in a box resulting in stubborn horizontal and vertical folds. The stubborn folds were a concern both for quality of image capture and for compression overtime which leads to tears.

Overtime, dyes begin to become brittle and flake, and/or cause the fibers below to become brittle resulting in loss.

Numerous small lateral splits in the barkcloth, areas of loss, and areas of potential loss presenting instability needed to be addressed before these items could be safely transported on a roll to the digitization studio. Before these concerns could be remedied, surface soil that would contribute to further deterioration or that would otherwise embed into the fiber of the cloth when moisture was introduced during humidification first needed to be removed, and the folds reduced.

Each piece of barkcloth was vacuumed through a screen with a Nilfisk HEPA vacuum, lightly humidified to relax the fibers of the cloth, and dried under weight. Very light weight was used so as to not affect the inherent textured quality of the cloth- just enough to reduce the stubborn folds.

(Left) Holes that occurred at the time of manufacture during beating were patched with small pieces of barkcloth. (Center and Right) Similarly, later repairs were made with recycled pieces of barkcloth. In these instances, the previous repair was left. The black tape shown in the rightmost image above however, was removed.

Areas of instability, like the ones shown below, were addressed by mending with a stable Japanese tissue of an appropriate tone and weight (to blend with the natural color and thickness of the cloth). Wheat starch paste was chosen as an adhesive. In previous testing, it proved to be the most compatible with the texture and finish of the cloth. Other adhesives, methyl cellulose for example, seemed to leave a shiny finish.

(Left column) Before treatment – recto and verso                                                             (Right column) After treatment –  recto and verso

Significant tears and loss required a different approach. The barkcloth shown below had a central vertical tear extending nearly the entire length (just under 8 feet). The dyes were brittle and flaking; the cloth on either side of the tear was also brittle, shredded, and mangled. Temporary reversible bridge mends were applied on the front to ensure that the design was aligned correctly. The cloth was then rolled, unrolled to have the underside face up, and mended on the verso (back).

(Left) Vertical tear extending nearly the full length of the cloth; (Center:top) Aligning areas along the tear prior to mending on the verso; (Center bottom and right) Temporary reversible bridge mends to hold cloth in position

(Left) After treatment recto; (Right) after treatment verso

Once treated, each item could be safely transported for digitization. Each side of each item required multiple shots (12-15 shots per side) that would then be stitched together using the camera software.

Simon Ingall, Digital Imaging Assistant, expertly facilitates the maneuvering and successful image capture of the oversized pieces of barkcloth.

Ideally, if space allows, barkcloth should be stored flat. Among this collection, those that fit in folders were stored flat in archival paper folders in flat file map cases. The remaining oversized pieces were rolled on archival tubes covered with ethofoam (for cushioning) and a Mylar cover (a barrier between the barkcloth and the ethofoam). The barkcloth was rolled face up with Hollytex interleaving (spun polyester web), labeled with thumbnail image and catalogue information, and returned to The College Human Ecology, Department of Fiber Science and Apparel Design for use in instruction and research.

While this treatment included practices commonly used in paper conservation treatments –  utilizing the same materials and stabilization techniques, working with laminate structures, and navigating over-sized items there are inherently unique qualities about barkcloth that required research, collaboration, and skills from allied conservation specialties. We are very grateful to our international colleagues at The Smithsonian Institution, Te Papa Museum, NZ, Bishop Museum, HI, and University of Glasgow for sharing their knowledge and expertise that only comes from the experience of working directly with these materials.

Below is a short video highlighting the treatment process of these items:

 

 

[1] Rowena Hill, “Traditional Barkcloth from Papua New Guinea: materials, production and conservation,” in Barkcloth: Aspects of preparation, use, deterioration, conservation and display, ed. Margot M. Wright (London: Archetype Publications Ltd, 2001), 33.

Due to the partial fermentation that occurs “activity from invading bacteria and fungi acquired during wetting and soaking, leads to a partial breakdown of the cell wall material helping to liberate pectin and hemicelluloses which normally cement the cells together ‘in vivo.” Thus dispersed, some of these binding chemicals get washed away, reducing the overall stiffness of the cloth. Those which remain ‘in situ’ help to thicken the fibers and bond them together in their newly aligned positions thereby strengthening the cloth.”

[2] Hill, “Traditional Barkcloth from Papua New Guinea: materials, production and conservation,” 34.

[3] Hill, “Traditional Barkcloth from Papua New Guinea: materials, production and conservation,” 35.

[4] Hill, “Traditional Barkcloth from Papua New Guinea: materials, production and conservation,” 35.

[5] Hill, “Traditional Barkcloth from Papua New Guinea: materials, production and conservation,” 41.

“Less of You; More of My Ancestors” | Part I

J. M. Iacchei

Our work in Conservation requires collaborative efforts with our colleagues throughout the library. Digitization projects are becoming increasingly more common. Together with Digital Consulting & Production Services (DCAPS) and the College of Human Ecology, Department of Fiber Science and Apparel Design, we recently treated 12 pieces of Polynesian barkcloth, also called tapa, from the Cornell Costume and Textile Collection.

Barkcloth, called siapo by the Samoans and Futunans, ngatu by the Tongans and Uveans, ahu by the Tahitians, masi by the Fijians and kapa by the Hawaiians, is widespread. Historically produced throughout the Pacific, Eastern Asia, and Africa, this cloth-like material is made from the inner bast fibers of select plants. The most prevalent fiber source throughout the Pacific was the Broussonetia papyrifera of the Moracaea family, more commonly known as paper mulberry. Depending on geographic region, other varieties of the Moraceae Family were also used, notably the Artocarpus (breadfruit) and the Ficus (fig and banyan). [1] Additional sources of fiber were obtained from the poison tree (Antaruis Toxicaria) and the Mamaki (Pipturus Albidus), in the far eastern tropics and in Hawaii, respectively.[2] Each fiber produced a cloth of its own color, quality, and fineness. Traveling in 1769 with Captain Cook, Joseph Banks wrote, “of this thin cloth they have as many different sorts almost as we have of linen; distinguishing it into different fineness and the different materials of which it is made.”[3]

Paper mulberry does not grow natively on the Pacific Islands but must be propagated from cuttings or suckers. [4] 7000-9000 years ago (5000-7000 BC), the inhabitants of the Asian mainland began to migrate to the Pacific Islands.[5] Among the items of necessity that they would need on their sea voyage and upon their arrival for settlement (food, fresh water, livestock, and plants), they brought with them paper mulberry. Transporting paper mulberry required great care; its survival depended upon shelter from the saltwater of the ocean and the use of fresh (drinking) water to keep it alive.[6] This was not a risk-free undertaking, suggesting the significance of both the plant and the material made from it to the people who made the effort to bring it with them across such vast distances.

Traditional uses of barkcloth range from utilitarian household purposes (curtains, room dividers, bedding, mosquito nets, bandages, candle wicks) to ceremonial (burials, deaths, births, taxes to the chiefs, and offerings to the gods). Barkcloth as clothing seems to have been a privilege of the nobility, reserving certain fashions and coloring that could be worn only by select individuals. Barkcloth carried with it a symbol of wealth, second it seems, to finely woven mats, also given in events of gift exchange, as tribute, or tax.

The fundamental steps of barkcloth production are shared among practitioners of the craft; however, the specific processes involved vary by location. Harvesting, preparation, beating, implements used, decoration techniques, and patterns each contribute to the unique qualities and characteristics that make one place of origin distinct from another.

Historically, women were responsible the manufacture of the cloth, often taking place as a communal event. The degree of the men’s participation in this activity varied by island. On the whole, they were given the responsibility of making the implements needed for their manufacture – the wooden beaters and anvils, carved designs on bamboo stamps, and wooden printing boards. It was the women of the village who were responsible for the harvesting of the bark, the beating and manufacture of the cloth, the preparation of the dyes, and the construction of the vegetal (pandanus leaves, coconut midrib, sennit) printing tablets used in their decoration.

In very general terms, the practice was to harvest the fiber, separate the outer bark from the inner bark which was then cleaned and beaten on a wooden anvil. The cleaned thin strip of bark was laid on an anvil, often hollowed for resilience and musical resonance, and beaten until it became a soft, widened, thin piece of cloth expanding in width from about 2 inches to 14-18 inches. Larger pieces of cloth were made by overlapping the edges of smaller beaten strips and adhering them together with a starch adhesive (arrowroot). Thickness was determined by the number of layers, usually 2, but more (4-5) for items like bedding. With the exception of traditional Fijian cloth, the practice was to lay the upper layer perpendicular to the lower.

Above: Wooden mallets (beaters) used to transform the strip of inner bast fibers into a soft widened piece of cloth. (Images from: Brigham, William T. Ka Hana Hapa: The Making of Barkcloth in Hawaii. Memoirs of the Bernice Pauahi Bishop Museum of Polynesian Ethnology and Natural History, Vol 3, Honolulu, HI: Bishop Museum Press, 1911.)

Various beating methods were found throughout the islands including: folding and beating in bundles, beating strips individually, and felting. The sides of the wooden mallets (beaters) used to beat out the bast fibers were grooved, often in varied width and depth, with at least one side left smooth. Initial beating was done with the coarser side of the beater, moving progressively towards the smooth. In Hawaii, this process was at times taken one step further – giving a final beating with a beater with a carved surface (far right image above) to impart texture and pattern into the finished cloth.

Above is an example of barkcloth without a printed design. Right: A detail of the image on the left showing the texture imparted by a patterned I’e kuku (beater)

Methods of decoration found among barkcloth varied by location. There was some overlap, but distinct practices, patterns, motifs, and overall look to a finished cloth by island developed. The designs and patterns are applied by a variety of methods: freehand, stencils, stained with local dyes, smoked, and/ or printed.

Left: Freehand; Center: Stenciled; Right: Freehand over printed design

Before the introduction of synthetic dyes, native plants were used to create dyes and impart color to a finished cloth. It is no longer known exactly how these dyes were made, but it is know that they were often made from the bark, fruit, and roots of local flora. For example: brown from the bark of the candlenut tree, reddish brown from the bark of the Bischofia javanica, black from the soot of burnt candlenut kernels, and yellow from the root of the Curcuma viridiflora.[7]

One method of design application, practiced in Samoa, Tonga, and Fiji, is the use of design tablets or printing mats to transfer an image onto the cloth. These mats and tablets, called upeti in Samoa, kupesi in Tonga, and kupeti in Fiji, were constructed of two layers of pandanus or coconut leaves. The top layer carried a relief pattern most commonly created from pandanus leaves, sennit, coconut midribs, bamboo, and hibiscus fiber. A rubbing technique was used to transfer the relief pattern to the beaten cloth.

In 2012, I visited the Field Museum of Natural History in Chicago while researching barkcloth as part of a final project at The University of Iowa Center for the Book. Shown above and below are some examples of Vegetal printing mats from that visit.

Recto, verso, detail: The origin of this cloth was labeled as “unknown”. The patterns seen on the verso are indicative of the use of a vegetal printing tablet. Considering that this method was used most notably in Samoa and Tonga, and the designs are similar to known cloths of each location, it is likely that one or the other is the place of origin.

Recto, verso, detail: The origin of this cloth was labeled as “unknown”. The patterns seen on the verso are indicative of the use of a carved wooden printing board. Considering that this method was used most notably in Samoa and Tonga, and the designs are similar to known cloths of Samoa, it is possible that Samoa is the place of origin.

On Samoa, the use of vegetal upeti began to decline in the 1930’s after the introduction of metal tools proved the use of carved wooden upeti a more durable alternative. About this change, Patricia Lorraine Arkinstall quotes Margaret Mead writing in 1930: “But so well defined is the province of tapa making as women’s work, that men have not exercised their imagination on the carving of these boards.” Arkinstall further adds, “Thus, the patterns on the rubbing boards have become somewhat stereotyped. The women are not happy with the situation, but since wood carving has traditionally been men’s work, they do nothing but sit by as their patterned tapas become less and less interesting.” [8]

The Importance of Conserving Barkcloth

Because production of barkcloth has ceased in the majority of the islands, the methods of production originally used by the ancestors of today’s inhabitants are not wholly known.

The effects of European influence and missionary initiatives began to heighten during the 18-19th centuries. The introduction of European cloth, synthetic dyes, and the replacement of vegetal design tablets used in Tonga, Samoa, and Fiji with wooden ones are a few examples. By 1890, production of barkcloth in Hawaii had ceased.[9]  Adrienne Kaeppler, of the Smithsonian Institution, noted that by 1984 of the Polynesian Islands, only Tonga, Samoa, and Fiji were still producing barkcloth. [10] With few exceptions, the production and high cultural regard of barkcloth has waned and current manufacture is produced in lesser quality for the tourist market.

The indigenous technologies that were once used have been altered, and over generations,  have become lost to unrecorded history and memory. Because nothing of equal quality is being produced today, conservation efforts to identify the material, environmental, and technological influences responsible for current condition are necessary in order to determine appropriate treatments. In preserving these materials, an abundance of cultural, historical, sociological, and artistic information is retained for further research and study of the Pacific Islands and Pacific Island culture.

Read more about the treatment of this collection in Part II.

[1] [1] Neich and Pendergrast, Traditional Tapa Textiles of the Pacific, 9.

[2] Leonard and Terrell, Patterns of Paradise, 13.

[3] Ann Leonard and John Terrell, Patterns of Paradise: The Styles and Significance of Bark Cloth Around the World (Chicago: Field Museum of Natural History, 1980), 22.

[4] Neich and Pendergrast, Traditional Tapa Textiles of the Pacific, 9.

[5] Rod Ewins, Bark-cloth and the Origins of Paper”(Paper presented at the First National Paper Conference, Hobart, Australia, 1987), 13.

[6] Ewins, “Bark-cloth and the Origins of Paper,” 13.; Anthony Meyer, foreword to Tapa: Bark Cloth of Oceania, written by Pascal Cusenier (Paris: Galerie Meyer, 1998), 2.

[7] Kooijman, Simon. Tapa in Polynesia. Bernice P. Bishop Museum Bulletin 234. Honolulu: Bishop Museum Press, 1972, Table E.

[8] Arkinstall, Patricia Lorriane, A studty of barkcloth from Hawaii, Samoa, Tonga, and Fiji: An exploration of the regional development of distinctive styles of barkcloth and its relationship to other cultural factors, Thesis, 1966, p119.

[9] Arkinstall, Patricia Lorriane, A studty of barkcloth from Hawaii, Samoa, Tonga, and Fiji: An exploration of the regional development of distinctive styles of barkcloth and its relationship to other cultural factors, 109.

[10] Mary J. Pritchard, Siapo: Bark Cloth Art of Samoa (American Samoa: Council on Culture, Arts and Humanities Special Publication Number 1, 1984), vi.

 

A leaf from a Persian Manuscript, circa 15th century

J.M. Iacchei

Image hand-drawn directly from: Hunter, Dard. Papermaking: The History and Technique of an Ancient Craft. New York: Dover Publications, Inc., 1943.

The map above shows the spread of papermaking from China west to Korea and Japan, its spread East across the Chinese empire to Samarkand, then to Europe, and finally to the Americas. What is fascinating about this map is the amount of time papermaking took to spread from East to West – over 600 years to reach Samarkand in the 8th century and over 1000 to reach Moorish Spain in the 12th century.

The basic principles of papermaking are shared among Eastern and Western methods – fiber source, fiber preparation, beating, sheet formation, drying – but the raw materials selected for fiber, the local conditions, and the methods used to carry out each of these steps varied by region resulting in finished papers of distinct characteristics and qualities.

Some of the finest and most beautiful papers were said to come from the Islamic lands. These papers, made from flax or hemp rag fibers, were highly burnished with a stone giving a very smooth surface. The calligraphy and illuminations that were composed upon these papers were as remarkably beautiful as the surface on which they were inscribed.

Shown here is a manuscript brought to the lab to be removed from its mat, treated for digitization, and then rehoused. The new housing – a double-sided window mat with hinged cover allows both sides to be viewed.

Before treatment: recto and verso

After treatment: recto and verso

Double-sided window mat: recto and verso

Additional information about Islamic Papers can be found:

Bloom, Jonathan M. Paper Before Print: The History and Impact of Paper in the Islamic World. New Haven: Yale University Press, 2001.

Soteriou, Alexandra, Gift of Conquerors: Hand Papermaking in India. Ahmedabad, India: Mapin Publishing, 1999.

Repairing a 17th c. pop-up book!!!

Caitlin Moore

 

“Pinax Microcosmographicus” came to us from Cornell’s Rare and Manuscript collection, in preparation for being displayed in an upcoming exhibit. The deceptively plain vellum binding with tattered ribbons hides a remarkable 17th c. “pop-up book”!

These anatomical drawings are constructed in such a way that you can lift various flaps to see different layers of the human body and other hidden images.

The first issue I chose to address was the binding structure. The book consists of four sections sewn on vellum tapes which are laced into the covers. The first page of each folio has a stub that wraps around the back of the inner folio to be sewn through. These stubs had broken and been pushed under the previous section.

I humidified each stub and coaxed it back to it’s original position. I then reinforced weakened areas with Japanese tissue and wheat starch paste to prevent the tabs from coming back through without affecting the flexibility of the structure.

Many of the flaps had become weakened and were curling or creased from time and use. The curling flaps were at risk of being crushed when the pages were turned or the book closed. This required localized humidification which was carried out using very slightly dampened pieces of blotter to relax the paper followed by dry blotter and weight to make sure the paper dried in the correct position. Blotter was also inserted behind the page to draw the moisture through the paper and a sheet of mylar protected the page beneath from any moisture that might carry through.

Once the flaps were flattened, I repaired all edge tears and some of the smaller pieces such as this foot which had to be reinforced as the small toe was beginning to detach and had to be consolidated.

Then came the ribbons… The ribbons were a mess, they were frayed and twisted and looked beyond repair.

I decided to alternate lightly humidification of the ribbons and gentle reshaping with my fingers. This took a considerable amount of time but eventually they became flatter and I was able to start sorting out the fraying fibers. I used a small awl to gently separate the fibers and put them back into position.

I contacted a local textile conservator and asked for advice on consolidating the ribbon. I had planned to back the frayed bits with a tinted tissue. The textile conservator agreed and suggested using Methyl Cellulose instead of paste to attach the tissue. I then used acrylics to tint a lightweight hanji paper to match the color of the ribbon.

I attached the tinted tissue to the ribbons with Methyl Cellulose as suggested and let it dry under weight. This was repeated on all four ribbons with great results!!

Finally I built a drop spine box to protect the book. I added velcro closures to ensure the box would keep the vellum covers in place should they start to warp. You can see the Pinax Microcosmographicus in the artist book exhibit in Kroch Library opening June 8!!!

 

 

 

Selfies and Snapshots: What’s in Your Closet?

Michele Hamill

Due to the rise of digital photography, photographs are being shared faster and in unprecedented volume than ever before. To learn more about your digital photographs, this Library of Congress resource is a good place to start.

Some credit the first selfie to Robert Cornelius who took a daguerreotype self-portrait in October, 1839. This image, courtesy of The Library of Congress, is believed to be the earliest extant American portrait. Learn more about the fascinating effort currently underway to document Cornelius’ photographs here.

In addition to the plethora of digital photographs, family collections include prints, snap-shots, and studio portraits that form the pictorial history of generations of family members.  Let’s take a look today at some of the types of photographs in family collections.  (And, by the way, an interior closet on the main floor of your home, is a great place to store your family photographs since it tends to maintain a stable temperature and humidity.)

A daguerreotype (1839-1865), like the Cornelius self-portrait, is a treasure in a family collection. It is one of the earliest types of photographs and was most popular from the early 1840s to 1860. Daguerreotypes are comprised of a silver-coated copper plate housed in a sealed package behind glass. The sealed package sits in a protective hinged case made of wood covered by leather, cloth, or paper. Daguerreotypes have a highly polished, mirror-like surface and are often hand-colored with pigments.  They are complex, unique objects that deserve special care.

An Ambrotype, most popular in the late 1850s, is another type of cased photograph, but they differ from daguerreotypes because the emulsion containing the silver image is coated on a sheet of glass rather than metal.  Ambrotypes were a popular means of portraiture and were an economical alternative to daguerreotypes, but were largely replaced by tintypes, which were even cheaper, faster, and easier.

Tintypes were popular from the start of the Civil War until the 20th century. They were less expensive than cased photographs, and they were made on coated iron, not tin. They were placed in paper mats or albums, or left loose, as in this example. Tintypes are most commonly found in the carte-de-visite size (approx. 2 ½” × 4″ to 4 ¼”). Because they often have no protective covering, tintypes are frequently dented, scratched, or rusted.

Albumen photographs were most popular from 1850-c. 1895. They have a silver image in an albumen emulsion coated on thin paper, like this cabinet card portrait. Albumen, the white part of an egg, was the most common emulsion for 19th-century prints. To make them studier, most albumen photographs were mounted to a secondary support or card. Cabinet refers to the format used to present the image, not the photographic process used to create the image.  Cabinet cards measure approximately 4 ½ by 6 ¼ inches and often have information about the photographer or studio which is useful for dating and identifying images. Albumen was gradually superseded by gelatin and collodion printing-out papers around 1885.

Another format of the albumen print is the carte-de-visite – which, at 4 ¼ by 2 ½ inches, is smaller than a cabinet card and about the size of calling cards or modern-day business cards. They were an enormously popular form of presentation for 19th-century portraits.

Printed-out photographs, such as this 19th-century cabinet portrait, have a warm brown-purple image rather than a neutral tone, because the silver image was formed from “printing-out” in daylight, not from chemical development. Printed-out photographs can look similar to albumen prints but have a major difference.  Printed-out photographs have a very white baryta layer between the paper support and the emulsion. Emulsions for printed out photographs can be either gelatin or collodion.  Many glossy collodion prints exhibit a subtle iridescent effect on their surface.

Cyanotypes, most popular from 1880 to the 1920s, are readily identified by their distinctive blue color, which results from using iron rather than silver as the image material. Family collections often contain cyanotypes, because their low cost and easy processing appealed to amateur photographers.

Crayon portraits, popular from the 1880s to the 1920s, were enlargements that could be life-size. They were made using a weak photographic base extensively hand-colored with pastels and charcoals, among other artist materials. Crayon enlargements were sometimes mounted to cloth and often placed in decorative frames. This 19th-century crayon enlargement shows the line of discoloration in the upper right corner where the cracked glass of an old frame let in atmospheric pollutants. It also shows overall darkening from damaging light exposure. The edges were protected from light exposure by the frame. Crayon enlargements can be brittle and are best stored in shallow boxes.

Platinum prints (1880-1930), in which platinum and not silver is the image material, have rich details, a velvety black color, and good image stability with no fading. Platinum prints were often used for studio portraits presented in a folder format. The characteristic image transfer of a ghost-print to the paper folder helps identify this print as platinum.

This 20th-century, silver gelatin, black-and-white snapshot shows one of photography’s popular themes: children.  People, pets, weddings, and vacations are common subjects. The image is made of silver suspended in a gelatin emulsion, the most common emulsion used for photographic prints in the 20th century. Remnants of the black paper corners are not harmful and can remain.  This wedding portrait was well-processed and remains in superb condition.

Most postcards were made using ink printing process, like lithography.  However some postcards are true photographs, or “real photo postcards”, with a postcard back, such as this silver gelatin postcard.  There are many resources to learn more about the history of postcards and for dating the stamp box found on real photo postcards.

Sepia-toned silver gelatin photographs, like this portrait in its complementary brown presentation folder, were created by toning 20th-century black-and-white photographs to a warm brown or “sepia” reminiscent of the 19th century. Sepia-toned photographs are very stable and show little image deterioration or fading. Because the brown folder is the original presentation for this photograph and is not causing damage, the folder and photograph can remain together.

Hand-colored silver gelatin photographs, like this example from the 1940s, were an early attempt to bring color to black-and-white photographs using artist’s materials. For this 1940’s print, dyes (which readily fade) were used to color the image.

Color photographs formed the largest segment of the snapshot market, beginning in the 1960s. Dyes used in color prints are prone to fading, exacerbated by light and heat. Early color photographs often show fading, or a shift in color, where one color predominates. Improvements in the 1990s resulted in longer-lasting color images.  These 3 color photographs show fading (left), color shift (middle), and modern color (right).

Polaroids, most popular in the 1970s and 1980s, often have a distinctive white border as in this example. They were a form of instant photography with do-it-yourself appeal because they did not require processing in a darkroom. Polaroids are one-of-a-kind images, because no negative is created in the process, so they may be unique images in a family collection. They can suffer from stability problems, including fading, cracking, and delamination.

Digital prints can be made using a variety of processes, including ink-jet (the most common printer used at home), electrophotography (office color printers), digital photo processors (used in many photo labs to print snapshots), and dye sublimation (used to make prints at photo kiosks). The stability of the digital prints depends on the process used to make them, the combination of the inks or dyes and paper used, and how they are stored and handled.

Here are some great resources for more information about family photographs:

The Graphics Atlas is a sophisticated resource that presents a unique, object-based approach for the identification and characterization of prints and photographs.
http://www.graphicsatlas.org

The Preservation Self-Assessment Program (PSAP) from the University of Illinois Library has a great format ID guide:
https://psap.library.illinois.edu/format-id-guide

And from the Getty: The Atlas of Analytical Signatures of Photographic Processes
http://www.getty.edu/…/publicat…/pdf_publications/atlas.html