Specialty Sessions – Page 11 – AIC Blog Archives: Conservators Converse

44th Annual Meeting & 42nd Annual Conference – Objects Session, May 17, 'Using Heat and Cold in the Treatment of a Lakota Winter Count,' Madeleine Neiman and Nancy Odegaard

Madeleine and Nancy presented a very interesting talk that shared their experiences using cold temperatures to achieve a specific treatment goal. Nancy began by introducing the object, a Lakota Winter Count. The object is one of a type of pictorial calendars that depict the history of the community and serve as a counting device. A historian would have been in charge of the count, naming years for remarkable events related to astronomy, the environment, or culture. Tribal keepers knew the name of the years, helping them to recall the oral history of the community.
The Lakota Winter Count that inspired this talk is from the Heard Museum in Phoenix, Arizona. At some point in the past, it had been folded so that the pictograph surface faced out. The interior surface had become stuck to itself, preventing the unfolding of the object. As the Heard Museum does not currently have a permanent conservation staff, the object was brought to the Arizona State Museum for treatment.
The primary goal of treatment was to unfold the count, enabling the viewer to see all of the pictographs at the same time. Additionally, there is bleeding, mold, darkening, and tears on the support. There was no history of fabrication or provenance associated with the object so the Arizona conservation team undertook documentation and investigation.
There are 121 pictographs on the non-coated side of the support that documents the years 1799 to 1918. The outlines are drawn in graphite and the limited additional pallette is consistent with other winter counts. These include two browns, a bright pink pastel, and blue and orange colored pencils. Specifically, the Heard winter count is very similar to a Long Soldier Winter Count at the NMAI. Sometimes, duplicates of counts were made for use or for sale, which could explain the similarities of the two pieces that cover roughly the same period. The Heard count is likely from a similar region in North Dakota.
The object was analyzed and the support was determined to be a piece of commercial oilcloth. FTIR showed the oilcloth coating is linseed oil and shellac. Fiber samples taken indicate that the fabric is cotton. This is consistent with commercial oilcloth produced in the late 19th, early 20th century; during this time period, commercial products began to replace local materials. Maker’s marks on the oilcloth identify the manufacturing company and Nancy and Madeleine shared contemporary advertisements, which demonstrated the prevalence of the product in the average household. The mark gives a terminus post quem of after 1901.
The fusing of the oil cloth to itself was likely due to ambient heat. A 1-2 cm opening along the edge was the maximum access before treatment. Dave Smith, conservation scientist at Arizona, was able to determine the glass transition period of the oilcloth coating is approximately 31⁰C. The average temperature in Arizona exceeds this from April to October, so the environment could have caused the shifting in the structure of the materials that led to the current sticking.
Madeleine undertook testing to explore options for opening the count. Organic solvents were not effective as the coating is cross-linked and now impervious. At this point, it was clear that whatever treatment was applied would be time consuming and invasive. The conservators asked the curators how crucial the treatment was to the object; however, the curators said that the current condition was fundamentally comprising the interpretation of the object as the chronological reading of the object was disrupted.
Knowing this, the conservators went back to the drawing board. Dave suggested considering cold temperatures, because polymers are long chain molecules whose movements are highly linked to temperature. If the temperature is below the Tg, then the polymers can no longer stretch and instead cleave, allowing for the two sides to be separated. Conservators tried compressed cooled CO2 gas, which was not effective. Similarly, overall freezing works at first, but the object warmed up too quickly for this to be viable for treating the whole object. Next, they used a Peltier cooler to apply repeated cold in a smaller area. The team worked to retrofit a USB beverage chiller to be able to consistently apply a 5⁰C. This system was used by applying the cooling plate to oilcloth surface for three minutes, then lifting the device so that Madeleine could use a stainless steel spatula to cleave small sections of the cloth from the opposite surface. She continued in this way for three months, working on the project for portions of each day.
After the cloth was opened, treatment turned to the tears, some of which appear to be linked to earlier attempts to force open the oilcloth. Stitching the tears was not viable because there was no safe place to secure the tears given the nature of the oilcloth. Adhesive backings also were not expected to be successful, as they would likely curl away from the coated surface over time. Instead, Madeleine found that by applying granules of textile welding powder to individual warps and wefts, she could control her mends and allow for a degree of reversibility. This process required four steps: relax the creases using Gortex, Dartex, and weights; pull misaligned fibers back into place; reweave fibers where possible; and, apply the granules of adhesive. The granules were heated in situ to a temperature at which they began to soften but did not completely solubilize, so that individual granules could then be mechanically removed if necessary. In some places, a secondary support was added where there were not enough wefts or warps. Small pieces of Remay were torn to the right shape, toned with dilute acrylics, dusted with the welding powder, and heated between silicone release paper in place.
Thus, the treatment presented benefited from the use of both low heat and cold temperatures. It was highly time intensive; however, this was considered justifiable as the object was a special project. The speakers also encouraged conservators to consider the use of cold for other treatment applications, as it seems to be underexplored when compared to higher temperatures.
After the presentation, one question was asked:

Q: Why did they not just heat the oilcloth coating to past the glass transition temperature? A: Doing this would likely have caused the cloth to become more sticky, more bonder, and more flexible. When the polymers are cold, they want to break due to the brittleness. The weakest point of contact in this case was with the other side, so cleaving the polymers facilitated the treatment goal.

This post was written from my personal notes, which may contain errors or inaccurately represent the author’s original intentions.

44th Annual Meeting- Book and Paper, May 17th, 2016: "A Protocol to Conserve Glazed Paper after a Water Damage." by Celine Allain

This talk was given by Céline Allain of the Bibliothèque nationale de France (BnF), after the lead author, Lucille Dessennes, also of the BnF, was unable to attend the conference.
In 2014, a pipe burst in the BnF, causing damage to 12,000 books, mostly from the 18th and 19th centuries. 360 of these 12,000 items contained coated papers, and when the disaster salvage/freeze drying contractors arrived on the scene, they would not accept books with coated pages for treatment.
The emergency team at the BnF instead had to use 6 freezers at the BnF to freeze-dry the 360 books with coated pages, although 51 of the 360 were too dry to be freeze-dried. Allain spoke to how difficult it was for the emergency team to accurately identify which books had coated pages—whether because the feel and look of the papers can vary or there might only be a few coated papers in a volume— and encouraged the audience to train emergency response teams to recognize coated papers beforehand. The difference is rarely as easy to identify as in the graphic below:

A common theme through the talk was the importance of keeping coated papers wet until they can be frozen. Even in the 2-3 hours it took the emergency team to arrive and place books in freezers, a number of books with coated papers had to be frozen “half-dried,” which limited the recovery outcome for these books. Had the books been kept wet and then frozen wet, they would have fared better.
Allain addressed the makeup of coated papers in order to explain why the pages should be kept wet: the coating (a mixture of pigments, binders, and other elements to improve opacity or water resistance) swells in the presence of water, readily attaches to the wet coatings of facing pages, and congeals into a “block” of stuck pages upon drying that cannot be separated without delamination of the paper surface. When the coated papers are still in a wet state, however, the pages can still be separated without loss of content.
The standard treatment for drying coated papers is freeze-drying (see below Further information), as long as there it is not a vacuum-thermal drying procedure. This allows the frozen water to sublimate.
For the 51 books that had been frozen half-dry, however, there were some that had blocked pages that needed to be un-blocked. The authors adapted a number of treatments to the books, including using a Teflon spatula to separate pages while still frozen.
The authors knew from previous research into the paper industry that the main binding agent in the papers was styrene-butadien latex (LSB in French, SB latex in English), which is soluble in tetrahydrofuran. Because the tetrahydrofuran’s toxicity made it too dangerous for use, Allain and Dessennes consulted the solubility triangle to arrive at a less toxic solvent. Using a mixture of toluene and ethanol (50/50 vol/vol), the conservators were able to attain equivalent solubility parameters and un-stick blocked pages of the affected books. The conservators brushed on the mixture, softening the SB latex, and then used a stiff spatula to separate the pages. The work is done in a fume hood. The authors noted that a large drawback is that the solvent can only be applied to specific areas of blockage and cannot be used on a large area or an entire book because the inks are frequently soluble in the solvent mixture.
Dessennes experimented with using the solvent in a solvent chamber, but speculates that because of the thickness of the block, that the vapors could not penetrate the interstices of the paper. Because of the limitations of the solvent applied as a liquid and in vapor form, Allain and Dessennes have plans to experiment with the solvent used in a low pressure environment.

Further information:
“Effet de la lyophilisation sur le comportement mecanique et chimique du papier, du cuir et du parchemin” Flieder, Francoise; Leclerc, Françoise; Chahine, Claire
Carlsen, Soren. “Effects of Freeze drying on Paper,” IADA Preprints, 1999, p. 115-120.
David Tremain on Emergency Drying of Coated Papers http://cool.conservation-us.org/byauth/tremain/coated.html
NEDCC leaflet on Freeze-Drying: https://www.nedcc.org/free-resources/preservation-leaflets/3.-emergency-management/3.12-freezing-and-drying-wet-books-and-records
CCAHA on freeze-drying techniques: http://www.ccaha.org/uploads/media_items/ccaha-freezing-drying-techniques.original.pdf
NARA on efficacy drying techniques: http://www.archives.gov/preservation/conservation/drying-methods-02.html
LOC on drying techniques, what to do if collections get wet: http://www.loc.gov/preservation/emergprep/dry.html

44th Annual Meeting & 42nd Annual Conference – Objects Session, May 16, "The Aftermath of Mends: Removing Historic Fabric Tape from Tlingit Basketry" by Caitlin Mahony

The Aftermath of Mends: Removing Historic Fabric Tape from Tlingit Basketry, presented by Caitlin Mahony and Teri Rofkar
The talk began with an introduction from Teri, who reminded us to be thankful to the caretakers of the land in Montreal. She and Caitlin then shared their presentation of a Mellon fellow project at the National Museum of the American Indian on removing a series of historic mends from Tlingit basketry. This project served as an opportunity to “reactivate” the baskets in their collection.
Teri read from a book entitled for Healing Our Spirit, sharing a Tlingit Oratory which advocated us to “apply kindness to open wounds,” an interesting perspective on the state of the baskets prior to conservation.

After seeing the image above of one of the first mother baskets, the audience was introduced to the history of Tlingit basketry. The primary material of these baskets is spruce root, some of which is dyed. Originally constructed as functional objects, they were eventually woven for the tourist trade, which helped the community transition from a subsistence to a market economy. When in use, Teri mentioned the baskets could be expected to have approximately a 100 year life span given heavy use.
There are now over 700 Tlingit baskets in the NMAI, many of which suffer from condition concerns. These include rips, tears, losses, and fold lines. Patterns of damage indicated that the dyed spruce root regions may be contributing to weakness. In 2011, the NMAI hosted a Mellon fellow research project that investigated the processing of spruce root at a cellular level. This set the stage for the more recent project which was focused on treatment.
In the first half of the 20th century, a repair campaign on pottery in the NMAI collection was documented. An image shared in the lecture showed a row of gentlemen seated behind a table covered with ceramics. A similar campaign was likely undertaken with the Tlingit baskets, though there is no documentation. Most of the repairs used hide glue or cellulose nitrate impregnated fabric strips that were painted with oil paints. Either the colors were never close matches or they have shifted significantly with time, but the repairs are currently aesthetically incongruous.
Of the 580 baskets investigated, 130 had historic mends. Of these, 24 had major repairs, which was defined as 20+ mends or a mend that obscured a sizable area of the wall or base. Tears were frequently found adjacent to these mends, likely due to the greater strength of the adhesive than the basket. Distortion was also noted, likely due to the effects of the drying of the adhesives. They also caused the removal or redeposition of tannins, dirt, and residue from the baskets, resulting in tide lines. Given the current condition, many of the baskets could not be exhibited, studied, or handled. Thus, the baskets were ‘inactive’ and no longer serving either their original or adopted functions.
NMAI hosted a three-day conservation workshop in April with representatives from museums with strong Tlingit basket collections. One goal of the workshop was to form an integrated protocol, as well as to study the technology and develop action points to create a path forward.
Since the workshop, NMAI has undertaken extensive documentation, consulted with the Tlingit community to correct and confirm catalog information, identified the wrapped weft material, which had been called false embroidery, and created digital reconstructions. These computer-generated images were created by Laurie Stepp and illustrate how the baskets would have looked when new. They also analyzed the color values, as the tannins are oxidizing and the dye fading.
After processing this information, experimentation was undertaken to develop a treatment approach. The primary goal for the baskets with major repairs involved taking down the fabric mends. Mockups provided by the Getty were used to test various methods. First focusing on the hide glue repairs, Caitlin found that water caused tide lines and blanching when applied with less control. However, when applied in the form of 2% agarose gel, the adhesive was softened and no tide lines formed. This approach was then used in treating the baskets. No barrier layer was necessary and they could work in multiple locations at the same time. They covered the agarose with plastic and gently weighted the gel to reduce evaporation and improve contact. Caitlin found a dwell time of approximately 45 minutes was effective. The fabric tape and residual adhesive could be mechanically removed with wooden skewers in the direction of the stitches; no adverse effects were noted from the treatment.
However, once the fabric was removed, areas of basketry were revealed whih had been protected from light exposure, indicating what the colors may have looked like when the baskets were first collected. This brought up the question of the aesthetic reintegration of the areas of previous repair. Conservators discussed this with curators and considered what the baskets might gain and loose through reintegration. The repairs are part of the baskets’ stories, but they are also visually distracting. This is an ongoing conversation.
Storage was designed for each object, based on individual needs and condition concerns. NMAI is also exploring how to improve access to this collection. They want to ‘reconnect the disturbed baskets’, and are currently loading tablets with the images and information which can be distributed to schools and used for other programs. An ongoing goal of the project is to continue collaboration between institutions to facilitate knowledge sharing. The NMAI also wants to connect with the contemporary weaving community, which Teri described as fragile, explaining that there were not many weavers 100 years ago and that there are even less now. Contemporary weavers work on commissions – so let’s ask people to weave again!
The talk ended with Teri saying, ‘Gunalcheesh, Ho, Ho. Thank you from the bottom of my heart.’ With this, she extended gratitude to the baskets and the remarkable women who wove them.
After the presentation, two questions were asked:

Q: Did NMAI find any traditional repairs? A: Yes, which included the weaving of new spruce roots, the combination of parts of baskets, such as the bottom of one with the walls of another, and the repurposing of large baskets to extend their lifetime.
Q: The agarose gel approach worked for the hide glue, what about with the cellulose nitrate mends? A: No, agarose did not work and acetone has negative effects on the baskets. They plan to try saturating the areas with D3/D4 silicone solvents to mask the materials and create a dam, but this is an aspect of future work.

This post was written from my personal notes, which may contain errors or inaccurately represent the author’s original intentions.

44th Annual Meeting & 42nd Annual Conference – Book and Paper Session, May 15, “All Over the Map: Bringing Buffalo’s Stars of Cartography to Light (One Lining at a Time) by Stephanie Porto

Stephanie Porto, Owner and Paper Conservator at Niagara Art Conservation, presented an engaging talk on the conservation of maps depicting the rapid growth of Buffalo, New York from 1805 to 1909, which were exhibited in “You Are Here: Buffalo on the Map.” Stephanie’s talk perfectly balanced the technical treatment aspects with contextual information on the maps themselves.

Image and exhibition outline found on: http://www.buffalolib.org/content/now-display/rare-book-room/buffalo-on-the-map.

Stephanie outlined the history and interesting facts of each map requiring conservation treatment. From the 1833 map, which detailed the area one year after Buffalo had been incorporated as a city, to the 1847 map which demonstrated the increase in commerce on the lake, and the 1893 Christian Homestead Association map, which included the salacious representation of 75 houses of ill fame.
Their conservation treatment needed to be completed in a limited timeline, and while six out of eight of the maps required linings due to poor quality paper, Stephanie found that traditional wet paste lining was not going to be possible in most cases. She included some great references that she had consulted on dry lining techniques:
Sheesley, Samantha. 2011. “Practical Applications of Lascaux Acrylic Dispersions in Paper Conservation”. The Book and Paper Group Annual 30: 79-81.
Jamison, Jamye. 2013. “Tip: Lascaux Linings in the Treatment of Park Plans for the Cleveland Public Library”. The Book and Paper Group Annual 32: 82-83.
Stephanie’s lining mock ups initially had an issue with sheen and planarity, but she was able to solve both problems using cellulose powder and a combination of Lascaux 303 HV and 498 HV. She outlined the specs of each adhesive, noting their difference in sealing temperatures (498 HV is higher) and final film elastic description (498 HV is hard and 303 HV is tacky). Stephanie described her preparation of the lining paper, beginning with rolling a 2:1 Lascaux 498 HV and 303 HV mixture onto silicone release Mylar with a brayer, allowing to dry, and ironing the dried adhesive film onto the lining paper, and using a printmaking baren to apply pressure after the film and paper were cooled. The map was placed recto up and the prepared lining paper was aligned underneath, the sandwich was flipped and smoothed by hand, then ironed from the center out. After being cooled, the lined map was pressed between Tycore panels. She then discussed the specific treatments of particular maps requiring linings.
The 1850 map depicting an 1805 Buffalo rendered in ink on watercolor paper required the removal of pressure sensitive tape, suction washing and cleaning, dry lining, and overall stretch-mounting.
The 1888 relief printed map could not withstand a backing removal, and so the treatment went forward with consolidation of delaminated paper with wheat starch paste set with a tacking iron, and a dry lining was applied with the original textile backing still in place.
The 1909 relief printed map was heavily water-damaged and retained evidence of previous conservation intervention. The map was consolidated with methyl cellulose, and was lined overall with the backing still in place with a Beva 371 film, and stretch mounted onto a foam board.
The 1893 color lithograph map required the removal of pressure sensitive tape, a temporary facing of 4% w/v Klucel G in ethanol during the backing removal, and a dry lining.
The 1833 hand colored lithograph was in the poorest condition with many detached fragments and a varnish layer. After the varnish was removed with ethanol, and the same temporary facing was applied, the backing was removed dry and the verso was then sanded to remove the adhesive residue. After lining with the Japanese tissue Okowara, the backing paper itself was hand toned with acrylics to integrate losses.
All the temporary facings were removed and loss compensation was completed by pouncing the Japanese tissue with cellulose powder and dry pigments. Finally, we got to see an excellent use of old chemistry textbooks in the pressing and flattening of the maps!

44th Annual AIC Meeting – Photographic Materials and Research and Technical Studies Session, May 15, "Colour Photographic Prints Brand by Spectral and Statistical Analysis", by Christine Andraud

Examples of chromogenic prints, at the Graphis Atlas website, with 10x magnification. Left: Kodacolor (1958); center: Kodak Royal Paper (May 1998); right: Fujicolor (1960s-early 1970s)

Heritage conservation tends to focus on what has been admired for many centuries. Other specialties, such as photographic materials, have only been around for a relatively short period of time. Photography is nonetheless a compelling medium with an array of different processes and variants within them. Research in this field shares the same goals as the one done for other materials: to better understand how, when and where objects were made, what conditions caused them to deteriorate and ultimately how to best preserve them. Studies such as the one presented by Christine Andraud at the AIC-CAC conference aims to bridge the knowledge gap in the field.
As Andraud states in her abstract, color photographs, particularly those classified as chromogenic, lack the kind of study that black and white processes have already received. This is exactly what caught my attention: why is that? Although we are now in the digitally born media age, color photographs have been commercially available since the late 1940s. Until not that long ago, they were the most common type of photographic technique, used by artists and amateurs alike. Today we can find examples of chromogenic prints in fine-art museums as well as in personal archives. Their widespread use is exactly the reason why they should be studied further.
For the purpose of identifying these types of prints analytically, Andraud used fiber optical reflectance spectroscopy (FORS). This is a non-destructive and non-contact technique that has long been used to analyze pigments in paintings. The same technique can also help us in the identification of dyes used in photographic emulsions. Better results are obtained when the device is placed in contact with the sample, but according to Andraud, this doesn’t seem to cause damage.
Dyes used in photography were not always the most chemically stable. In fact, their formulas changed often precisely to change this trend and improve their reliability. The appearance of these photographs can be quite different from the one they had when they were made. Consequently, their visible spectra have almost certainly changed. It is therefore considered more accurate to characterize these dyes in the near infrared region, where the organic functional groups’ fingerprint can more accurately be identified.
Using samples from known manufacturers and dates and the Fischer criterion’s statistical model, the author created a chromogenic processes database, to which other samples of unknown provenance can be compared to. So far, data has been collected for prints made from the 1960s up to the 2000s, by different manufacturers. Kodak samples seem to be the ones that yield better results so far (within 3% error). The author’s goal is to continue this project by analyzing more samples (particularly produced in the 1950s to 1970s) and therefore increase the accuracy of the obtained results.
This method seems to be very promising and I personally hope to hear about it again in the future.

44th Annual Meeting—Book and Paper Session, May 16, “A Low-Oxygen Capable Storage and Display Case for the Proclamation of the Constitution Act & Design of a Counterbalance Supporting Mount for the Book of Remembrance, Michael Smith and Eric Hagan

A Low-Oxygen Capable Storage and Display Case for the Proclamation of the Constitution Act
The first half of the talk was presented by Michael Smith, Collection Manager, Textual and Cartographic, Unpublished and Unbound, Library and Archives Canada, who discussed the construction of storage and display cases for the two original copies of the Proclamation of the Constitution Act.
There are two original copies of the important document, sometimes referred to as the “raindrop” and the “red-stain” copies. It was raining on April 17, 1982 when Queen Elizabeth II and Prime Minister Pierre Trudeau signed the Proclamation of the Constitution Act outdoors, and raindrops smudged the ink on one copy. The other copy, signed later indoors, was pristine until July 22, 1983 when Peter Greyson, a young art student from Toronto, requested to see the document at the Public Archives of Canada under the pretense of studying its design and calligraphy. As he leaned over the document, a pool of red substance spread over its surface. This was later found to be red paint coming from an Elmers glue bottle hidden in Greyson’s coat pocket. Greyson had defaced the Proclamation of the Constitution Act to protest a decision allowing the United States to test cruise missiles over Canadian air space. Conservation attempts to remove the stain from the paper were unsuccessful, and while suggestions were made to cut out the damaged area and replace it with a newly inscribed piece, the decision was made to keep the stain rather than carryout out a procedure would affect the document’s authenticity and integrity. The act of vandalism was the first time a document in the Public Archives of Canada had been willfully damaged, dramatically changing security and viewing procedures at the Archives.
The inks on both copies of the document were tested for light sensitivity, and studies concluded that the ink was extremely light sensitive. While designing the case for the Act in collaboration with CCI, Michael decided to segregate preservation components from security components, reasoning that it was stored in a secure vault for the majority of the time where security requirements would be fulfilled. The storage case with built-in compartments for silica gel and activated charcoal was designed to control humidity and oxygen levels, using OptiView™ UV filter/anti-glare glass to reduce UV levels. The document was secured in place using custom magnetic clips. The case was fitted with a Marvelseal® bag that expanded or contracted in relation to the atmospheric pressure in order to reduce stress on the glass. A display case was then designed to limit light exposure and for security during exhibition, using a layer of security glass, VariGuard Smart Glass™, and a top layer of glass for scratch protection. The VariGuard Smart Glass™ remains opaque to block light levels until a button is pressed to make the glass clear. In combination, the storage and display case made up two halves of one system for the security and preservation of the documents.
Design of a Counterbalance Supporting Mount for the Book of Remembrance
Eric Hagan, a conservation scientist at CCI in the Preservation Services Division, presented the second half of the talk on the design of mounts for seven books of remembrances displayed in the Memorial Chamber on Parliament Hill. A high profile project to craft six new altars for the books using stone, bronze and glass led to a condition assessment of the books by Christine McNair, who recommended a better support system for the books when displayed. As the pages of the books are turned daily during the Turning of the Page Ceremony, the books have to be fully movable and go through a range of motion. To provide suitable support for these working books was a fascinating design challenge.
The counterbalance support system for the First World War book served as an inspiration for the versions used to support the remaining books. Eric’s new design relied on a linkage connection using four bars to form a gravity-activated mechanism, mirroring the motion of the book while the leaves were being turned. The low-profile mounts were each made of 24 pieces of custom-made aluminium parts and other parts sourced from outside Canada. A different design for each book had to be made due to varying dimensions. A surface of bonded Volara® foam was used to provide cushioning for the books. Eric ended his talk by describing the completion of the mounts with a black powder-coated fabric cover. It was amusing how he thought the anodized aluminium was quite appealing, and had not thought of the need to make a cover until the topic was raised up! A difference in aesthetics—I suppose the sleek, matte-black look of the aluminium did not match the more traditional look of the Memorial Chamber.
It was fascinating to listen to Michael and Eric describing their problem-solving process to deal with the requirements and challenges they faced. I was particularly intrigued by Eric’s counterbalance support mount, since a book cradle that adjusts according to how a book opens seems to be the dream everyone tries to achieve in book supports. While the mounts were amazing, the high profile project of the Books of Remembrance meant that there wasn’t really a budget limit. In hopes of finding a more affordable solution, I asked Eric afterwards what the previous supports for the books were like, but was told that none had been used before—hence a real need for the new supports! I’m curious how sensitive the mounts are, and whether they only respond to the movement of the books they were made specifically for. The concept of a cradle that adjusts its shape according to the book could possible be great for digitization projects or for the idea of reusable cradles.

Joint 44th AIC Annual Meeting & 42nd CAC-ACCR Annual Conference – “Carlo Crivelli's St. George Slaying the Dragon at the Isabella Stewart Gardner Museum: Technique and Restoration.” Speaker: Gianfranco Pocobene, May 17

An Altarpiece Reunited. Isabella Stewart Gardner Museum. 2015. Web. 30 May 2016 <http://crivelli.gardnermuseum.org/altarpiece>.
Carlo Crivelli’s St. George Slaying the Dragon was completed in 1470 as one of six panels in the Porto San Giorgio Altarpiece. After the church was demolished in 1803, this altarpiece was disassembled and individual panels dispersed to collections throughout Europe and the United States. The Isabella Stewart Gardner Museum (ISGM) acquired St. George Slaying the Dragon panel in 1897.
Since arriving at the museum, Carlo Crivelli’s painting has undergone two conservation treatments: one by George Stout during 1934-1935 and the other by Pocobene and his team during 2013-2015. The 2013-2015 treatment was conducted in anticipation of the ISGM’s exhibition Ornament and Illusion: Carlo Crivelli of Venice (10/22/2015–1/26/2016). This was the first exhibition featuring Crivelli to be held in the United States and the St. George panel was selected to be one of the centerpieces.
St. George was constructed using traditional Venetian techniques and materials including egg tempera paint, ornamental relief, and gold leaf gilding. These layers were visible along some of the periphery edges. Worm tunnels in the upper right edge indicate the poplar panel had previously been trimmed-down, likely during the time the six altarpiece panels were separated. Low relief forms, known as pastiglia, were built-up in the armor, halo, forehead gemstone, and the horses bridal and reigns.
In preparation for the Ornament and Illusion exhibition, an extensive examination was performed including X-radiography, IR, RTI, XRF, and SEM analyses. The resulting X-radiograph revealed lead white in the original paint layers as well as dense lead putty fills during the previous restoration. Infrared reflectography revealed both carbon black ink underdrawing and contour line reinforcements in bone black paint (the presence of this paint made it difficult to discern the underdrawing). Reflectance transformation imaging revealed the fish scale textures in the armor and sword hilt. X-ray fluorescence revealed lead white, earth pigments, vermillion, red lake, and azurite in the blue-scale fish pattern, and silver in the armor (indicating that the brown-black color is actually tarnished silver leaf). Scanning electron microscopy analysis was performed by Richard Newman at the MFA Boston. After cross sections from the armor were analyzed with SEM, the presence of silver leaf was confirmed, conversion of the silver leaf to a silver sulfide, and a surface layer of bone black covering the leaf. In addition to the technical analyses, images from 1926 and documentation from the 1934-1935 restoration were also referenced.

During the 2013-2015 treatment, the cleaning process focused on removing grime, the old PVA varnish, yellowed wax coating, and old restorations that no longer matched the original paint layers. Fills, inpainting, and regilding was employed to restore the panel painting. In order to maintain its aged appearance, the 23k gold leaf and shell gold applied in a few selected areas of the sky and abraded pastiglia to reintroduce more vibrancy and hint at the original finish. If you would like to learn more about this treatment or about the Ornament and Illusion exhibition, please visit: http://crivelli.gardnermuseum.org/beneath-the-surface

About the authors:
Gianfranco Pocobene earned his M.A. in Conservation from Queen’s University and holds a Certificate of Advanced Training in Paintings Conservation from the Harvard Art Museums. For the past thirty years, Pocobene has worked as a paintings conservator in the United States and Canada, and for the past twelve years, he has been the John L. and Susan K. Gardner Chief Conservator at the ISGM.
Jessica Chloros earned her M.S. in Art Conservation from the Winterthur/University of Delaware Program in Art Conservation. For the past eight years, Chloros has worked as an associate objects conservator at the ISGM.
Richard Newman earned his B.A. in art history from Western Washington University, M.A. in geology from Boston University, and Certificate from the Center for Conservation and Technical Studies, Fogg Art Museum, Harvard University. For the past thirty years, he has worked as a conservation scientist at the Museum of Fine Arts, Boston. Newman is currently the Head of Scientific Research at the MFA, Boston.

44th Annual Meeting: Photographic Materials Session, May 16, "When Inkjet Prints Get Wet: First Contact to Weeklong Submersion," by Daniel Burge

As an emerging paper conservator, I was eager to attend Daniel Burge’s talk, “When Inkjet Prints Get Wet: First Contact to Weeklong Submersion.” I wanted to expand my understanding of this type of print that seems to be so fragile and difficult to preserve. Is there any hope for these objects after a water emergency?
The aim of Burge’s research was to critically assess the damaging effects of water on modern inkjet prints to develop disaster response protocols that maximize emergency response and recovery efforts of a damaged collection. Many types of inkjet prints were immersed in water for increasing increments of time: 1 second, 10 minutes, 1 hour, 8 hours, 24 hours, 48 hours, and 7 days. Damage to the colorants, paper coatings, and paper supports were recorded. The majority of inkjet prints proved to be damaged after one second of immersion. Some inkjet prints remained fairly stable during extended periods of immersion. This allows an emergency response timeline to be made focusing rescue efforts on saving prints that have some stability when exposed to water.

IMG_20160516_103650 — Title slide of Burge’s presentation showing examples of damage to inkjet prints after submersion in water.

Burge’s research also revealed that pigment colorants were generally more stable than dye colorants; and prints made on polymer or uncoated fine art papers were the most susceptible to damage. However, some anomalies of the statement above were observed. Burge explained that stability is not only related to the materials incorporated in the inkjet prints but that it is also linked to the relationship between the colorant and the coating as well as the relationship between the coating and the support.
In conclusion, Burge stressed the following points:

Priorities may be assigned to a collection based on a thorough understanding of the colorants, coatings, and supports of inkjet prints coupled with the results of this research guiding emergency response efforts during a water incident.
Good housing and storage methods may help to reduce potential water damage.

Slide from Burge's presentation: Anatomy of a Water Damaged Print. — Slide from Burge’s presentation: Anatomy of a Water Damaged Print.

Several people added to the presentation through their questions and comments. All agreed that IRIS prints are incredibly sensitive to moisture. A question was asked, raising the ethics of printing a new inkjet print from a file to replace a damaged print. Burge replied that even though this is possible, there is a unique relationship between the artist and the original, damaged print. We should be considerate of the significance of the original before making a reprinted version. I felt that I had gained a better understanding of the issues surrounding the inkjet print’s sensitivities to water that would allow me to better care for a collection. I greatly admired Burge’s enthusiasm and authority in this subject matter as well as his poise as a speaker.
An overview of Burge’s project and helpful information may be found on the home page of the Image Permanence Institute’s DP3 Digital Print Preservation Portal under the ‘Flood’ tab: http://www.dp3project.org/

44th Annual Meeting, Objects Session, May 17th, “The Use of Gums and Resins in Archaeology and Microchemical Tests for their Identification,” by Christina Bisulca

Christina Bisulca presented a fascinating paper that not only described the source of and uses for pine resins and insect lacs but also detailed various methods of testing for these substances in the lab. The Arizona State Museum is home to a collection of 35,000 objects representing every major cultural group in the southwest from Paleo-Indian to the historic period. As part of a conservation and rehousing project made possible by a Save America’s Treasures grant, conservators hoped to analyze and identify adhesive resins present within the collection.

Map showing regions mentioned in the talk

Certain plants and insects are found only within particular regions of Arizona due to the huge range of elevation and environmental biomes within the state. Since three of the most prolific cultures, the Hohokam, Mogollan, and Ancestral Puebloan occupied very different biomes, it was assumed their use of natural adhesives would vary according to location.

The Hohokam, for example used creosote lac, a polyester resin derived from an insect on the creosote bush found in desert lowlands. On the more northerly Colorado Plateau, where the Ancestral Puebloans lived, piñon pine was a plentiful source of diterpenoid resin. In general, Bisulca and her team assumed insect lac was used in the south and pine resin in the north.
Initial analysis was done with Fourier Transform Infrared Spectroscopy (FTIR) but researchers had trouble gathering reference plant material. They also realized these high tech, expensive tests are not readily available to many archaeologists, so they used microchemical tests in addition. Since no reliable microchemical test existed for shellac the team developed one based on the pH dependency of color in anthraquinone dyes, which are extracted from lac insects in Asia. In alkaline conditions the dyes turn from orange to purple. The test worked 80% of the time even in their archaeological collection. Where it did not work the resin had likely been charred or highly heated. The results of the tests challenged their assumptions about pine resin being used primarily by the north. In fact the team found more insect lac in the Ancestral Puebloan collection than pine resin. The lac would only have been available to these regions through trade. The researchers also investigated the use of each material. Bisulca used arrows, common to all three cultures, to highlight the different uses for each adhesive. Insect lac is stronger and less brittle so was used by each culture, regardless of location, for hafting the arrowheads to the shaft.

Overall, Dr. Bisulca’s talk was extremely informative and used excellent images to portray her ideas. The images she used of the lacs and resins as they are found in nature and on ethnographic objects helped to clarify the differences between the source and use of each. I have to admit I had not considered the significance of these resins in terms of their use in tracing trade routes and cultural practices. I am curious to know what similar substances would have been used by Eastern and Plains area cultures and how well such resins would be preserved in damp archaeological environments. This will certainly change the way I approach native material at my own site.
All images are from a poster on insect lac by Christina Biscula available here.
Information about the authors is available from The Arizona State Museum’s website.

44th Annual Meeting, May 17, Objects, Conservation and investigation of ancient bodies at Abydos– Challenging work in post-revolutionary Egypt. Lucy-Anne Skinner and Mohamed Ahmed Ibrahim.

Lucy-Anne Skinner spoke about the conservation of human remains at the site of Abydos, Egypt. Working for the Institute of Fine Arts, New York University project, Lucy had to engineer some novel solutions when two unusual burials needed to be block lifted. Lucy explained that block lifting an entire burial is not common at Abydos, as most graves are fully excavated in the field. Two graves excavated in the 2012 season in the North Cemetery presented unusually complete assemblages of grave goods, with one wearing a beaded headdress over well-preserved hair, and these factors prompted the conservators to block lift rather than to try to treat the components in situ.

The team of workmen working with the conservator helped build a wooden frame and slide metal sheets underneath, so that the entire burial could be lifted. Foil was used as a barrier layer, and expandable spray foam was used to lock components into place so that the burial could be transported back to the lab and eventually (in another field season) flipped over to work from the bottom to stabilize the lower portion of the coffin before addressing the human remains and other components. Lucy showed many details of the extraordinary finds including beautiful hippo ivory clappers. Though this project began in 2012, conservation of the burials was only completed a few days before this talk was presented (really!). Political instability in Egypt and the extraordinary logistical challenges surrounding excavating in a country undergoing political and social upheaval complicated the timeline and created extra challenges for the conservators.

Transporting a block-lifted burial to the depot at Abydos, Egypt (image courtesy Abydos excavations, Institute of Fine Arts, New York University)

For me, the big takeaways were that conservation in the field requires a great deal of planning and then a lot of on-the-fly creativity. Many digs lack a field conservator, but clearly the planning and execution of this complicated project really benefited from having Lucy on site over the course of multiple seasons. The project took several years to complete, so communication and planning in the off-season was needed for a successful outcome. Particularly challenging issues of working within Egypt while in the middle of a period of crisis were dealt with admirably by Lucy and her colleagues.