Month: June 2017

45th Annual Meeting – Pre-session, May 29, 2017, “ECPN Poster Lighting Round,” moderated by Rebecca Gridley and Michelle Sullivan

This year ECPN rolled out a new program during a pre-meeting session that allowed poster presenters another venue to share their projects and research. I was very excited for this session because I have felt overwhelmed by the number of posters and limited free time to view them. A similar sentiment was later echoed at the AIC Business Meeting. I hope that ECPN (or AIC generally) considers organizing a similar session next meeting and I would encourage anyone looking for more engagement with poster authors to attend.

This session was in no way comprehensive of all the poster submissions. ECPN members received a notification about the session about a year before the meeting. However, ECPN contacted all poster authors once they were accepted to the general AIC poster session. The email solicitation encouraged “emerging conservation professionals” and “topics relevant to ECPs (not necessarily authored by ECPs)” according to Rebecca Gridley, ECPN Vice Chair and one of the organizers of the session. There were 14 presenters total this year, which were chosen from email responses of poster authors indicating an interest in participating. The final selection was chosen to offer a range of talks across specialties and include speakers spanning the ECPN demographic, according to Gridley. Unfortunately not every author interested was able to be included due to time restraints of the session, but ECPN is considering how this could be improved in the future.

This year’s inaugural Lightning Round did seem to have mostly young presenters including pre-program, graduate students, and recent graduates. It does seem that ECPN is trying to be more inclusive and the demographic of “ECP” is only loosely defined. Certainly the audience this year was more diverse than the presenters and included AIC Fellows and other more established professionals in the field. At the same time, the environment of the Lightning Round felt very safe and welcoming. We were seated at round tables, which was more casual than auditorium seating. This was a great opportunity for first-time presenters to get their feet wet. One of the speakers was a first-time attendee and presented on her first conservation treatment ever as a pre-program. This session promoted information sharing and dialogue—activities that I personally feel will only help strengthen our field.

Alex Nichols reflecting on the benefit of the Lightning Round said, “I was approached by several conservators and researchers in specialties other than my own [modern and contemporary objects] who said that they were introduced to my research through the lightning round presentations.” In comparison to the last time Nichols presented a poster (at the 43rd Annual Meeting in Miami), she had more people ask about her research, which she attributes to the exposure from the ECPN Lightning Round.

Cathie Magee presenting alongside Michiko Adachi at ECPN Poster Lighting Round. The moderators are seated at the table. 

The 14 poster topics were divided into two rounds, which allowed for a necessary intermission/bathroom break. The rounds were moderated by Michelle Sullivan, ECPN Chair, and Rebecca Gridley, ECPN Vice Chair.

In the spirit of the “Lightning Round” each presenter was given two minutes and three content slides to summarize their poster at the podium. This seemed like a daunting task and like I might not receive much more information than the title of the poster. I was really impressed with how clear and concise all the speakers were (I think the tambourine—symbolizing time’s up—only had to be used once). I learned a lot from the brief presentations and there was even time for one or two questions for every speaker. Having the visual component of the slides I felt took this beyond what a written abstract can offer. The Q & A was also very lively and I think emphasized how valued the poster presentations are to the conservation community.

I found this Lightning Round useful not only for the direct information, but also in helping me be more efficient with my time in the exhibition hall with the posters. Each PowerPoint included the poster number for easy reference to the location in the exhibit hall. Feeling similarly, Claire Curran, Assistant Objects Conservator at the ICA, also in attendance, and reacted, “definitely visiting this one—sounds really cool” in response to a treatment of a Hopi Katsina doll. The room was filled and there seemed to be a strong positive response to the session.

To keep things light and encourage additional networking during the ECPN Happy Hour (which immediately followed the Lightning Round) a fun fact about each presenter was announced in addition to his/her professional bio. For example, Sarah Giffin was introduced as the “meat whisperer” because of her delicious slow cooking brisket recipe.

I am embarrassed to say that I did not know that the posters are published on the AIC website after each Annual Meeting. You can access them here.

To help your exploration of the .pdf files online, here are some of the highlights each presenter chose to emphasize during the ECPN Lightning Round.

#30 Conservation in Miniature: The merger of museum object and historic interior in the treatment of a Victorian era dollhouse

Sarah Giffin

  • Applied in situ treatment methodology used for full-scale interiors to miniature interior of Horniman dollhouse
  • Mist consolidation with nebulizer using Klucel G in acetone (tests in water solubilized tannins in wooden walls creating issues with tidelines)
  • Condensation in the small tube was a challenge and had to tap out liquid droplets at times

 

#60 Conservation and Art Historical Data goes Digital at the Art Institute of Chicago

Kaslyne O’Connor

  • Interactive website for conservation treatment of a collection of Alfred Stieglitz photographs and some contemporaries
  • artic.edu/Stieglitz
  • Used WordPress platform because easy interface and allowed for frequent updates to content
  • Provides links to art historical information as well conservation/ technical information and research

 

#44 Applying Fills to Losses in a Flexible Polyurethane Foam Chair at the Museum of Modern Art

Alex Nichols

  • Research and analysis to confirm type of foam composition of the chair
  • Bulked methylcellulose and grated polyurethane foam for consolidation and filling of losses; liquid nitrogen helped harden foam enough to easily grate and shape
  • Inpranil DLV/1 is a traditionally favored consolidant for polyurethane foam but has been challenging to acquire

 

#92 Chemical Cleaning and Intervention Criteria in a Brass Dial Clock from the XIX Century

João Henrique Ribeiro Barbosa

  • Clock face (only surviving element of the clock) composed of three different metals joined together with rivets
  • Previous cleaning by polishing left white residues and new corrosion products developed underneath
  • Ammonium citrate solution addressed polish residues with “DTCNa” or sodium diethyldithiocarbamate solution addressed corrosion products

 

#24 History, Treatment, and Preparation for Digitization of 14th-century Estate Rolls

Annabel Pinkney

  • Surface cleaning, humidification, repair with Japanese tissue
  • Rehousing to handle during treatment, digitization, and future research

 

#42 Treatment and Reconstruction of a Badly Damaged Hopi Katsina Doll Made of Gourd

Hayley Monroe

  • Gourds painted in acrylic
  • Treatment included surface cleaning, consolidating cracks, introducing new internal armature to help with reassembly and stabilization
  • Used silicone self-adhering bands to secure while mends were setting
  • Armature was set in place before doll head was reattached; tensioned wire extending to wings before head was placed back on

 

#10 Towards Nondestructive Characterization of Black Drawing Media

Nathan Daly

  • Redon drawings were used for case study
  • Redon working period overlapped with commercial materials available in 20th century
  • Macro XRF scanning used to map elements combined with micro Raman spectroscopy
  • Characterization relied on peaks in fingerprint region and peaks indicative of known additives to distinguish between different carbon-based media
  • 785nm laser for Raman because of heavy use of fixatives on the drawings

 

#27 (I Can’t Get No) Documenation: Preservation reporting in the Archives

Marissa Vassari

  • Established a template “Preservation Report” for standardized documentation and condition reporting
  • Focus on up-to-date condition and documentation of current status of projects and personnel involved; address realities of institution with changing/temporary staff and disruptions project workflow
  • Format based on feedback from other institutions and existing condition reports in the archive

 

#80 Bedbugs: A pesky problem

Meredith Wilcox-Levine

  • Addressing infestation of a Lakota teepee in private hands installed behind owner’s bed
  • Freezing unsuccessful likely not able to achieve low enough temperatures throughout
  • “Solarization” using hatchback car appeared to work (i.e. no live bugs remained)
  • For domestic infestation chemical treatment often necessary for bed bugs; they are night feeders and hide during the day

 

#32 Treatment of a Shattered Bark Basket from Australia

Marci Jefcoat Burton

  • Basket likely eucalyptus bark sealed with natural resin
  • Consolidated with B-72; bridged with tissue and blend of Lascaux adhesives
  • Removable internal support for storage constructed of backer rod (trapezoidal shaped Ethafoam strips) shaped to the contour of the basket and padded with Volara

 

#84 Lifting the Microfiber Veil: Utilizing Evolon fabric at the Mauritshuis to remove aged varnish from Hendrick Heerschop’s A Visit to the Doctor

Julie Ribits

  • Evolon is 70:30 polyester: polyamide spun-bond fabric
  • Evolon originally developed as anti-bug fabric
  • Used to lift and remove aged varnish; gentle and appropriate for surfaces with extensive lead soap networks
  • Polyamide fibers are hydrophilic and contribute to aqueous cleaning

 

#22 Captain America Encounters Klucel M

Michiko Adachi and Cathie Magee

  • Captain America pages had been stapled together in case binding
  • Mending utilized solvent reactivated tissue to avoid solubility issues and tidelines from acidic migration of newsprint substrate
  • Klucel M used as adhesive because of strength and transparency
  • Klucel M artificially aged by Library of Congress and seems to have similar properties/behavior to Klucel G

 

#67 Initial Treatment Techniques for Japanese Lacquer-based Metallic Thread and Cut Paper Applique

Elinor Dei Tos Pironti

  • Solubility testing was used to characterize original adhesive for metallic paper threads on a Japanese garment
  • Urushi was used to consolidate metallic threads

 

#31 Under Close Observation: A pilot study monitoring change in objects’ conditions

Ashley Freeman

  • Summarizing current research and findings of the Managing Collections Environment Initiative at the Getty
  • Comparing different methods of monitoring conditions of objects including photographic documentation (DSLR, point and shoot camera, iPhone), caliper measurements to monitor cracks, acoustic emissions
  • 14 objects representative of materials found in institutional collections used for case study; exposed to humidity cycling

45th Annual Meeting – Unique Objects/Unique Treatment, Weds. May 31, 2017, “Nanocellulose films: properties, development and new applications for translucent and transparent artworks and documents,” presented by Remy Dreyfuss-Deseigne

Remy Dreyfuss-Deseigne described research related to mending methods for transparent materials using nanocellulose films. His research has been carried out with several institutional partners, at the National Library of France (BnF, Paris, France), Research Center for Conservation (CRC, Paris, France), French Museum of Cinema,  and during his 2015-2016 NEA fellowship in paper conservation at the Conservation Center for Art & Historic Artifacts (CCAHA, Philadelphia, PA).

Remy opened with some images of difficult structural problems: torn gelatin windows, animation cells, and architectural drawings on tracing paper. He then introduced nanocellulose, explaining how it is made, what its properties are, and its potential for use in conservation.

His work focuses on one kind of nanocellulose, microfibrillated cellulose (abbreviated MFC).  Nanocellulose materials are produced for a variety of uses in electronics and biotech, and are being researched and manufactured by several universities including in Grenoble, France  and at the University of Maine.

Nanocellulose is produced by mechanically shearing wood to rip apart the fibers until they are nano in scale.  Cotton, spruce and birch can all be used as sources for nanocellulose. The amorphous parts of the remaining cellulose structure are treated with acid in order to dissolve them, leaving highly crystalline fibrils.   There is a lot of ongoing research into the production of nanocellulose in the nanotechnology, renewable materials, and sustainable engineering fields.

Nanocellulose fibrils vs. crystals, image from: https://3dprint.com/69012/american-process-and-ornl-say-nanocellulose-will-rival-carbon-fiber-for-3d-printing/

 

For conservation applications, Remy compared the properties of nanocellulose films to  lightweight Japanese papers like gampi and kozo used to mend tears on translucent artworks. Nanocellulose is supplied as a gel that can be cast out by pouring into a petri dish and evaporating out the water, creating films that vary proportionally in thickness related to concentration. Remy’s research investigates its properties in combination with different adhesives, and its response to artificial aging tests (light, temperature and humidity) as well as mechanical strength tests.

He found that the nanocellulose films were thinner than papers but quite strong (nearly as strong as Gampi), and mostly behaved like cellulose, a good thing for their use as a paper conservation material. Most importantly, mends made with the thin films are practically invisible in regular and transmitted light. These mends were demonstrated on translucent slides with tears from the collection of the  French Museum of Cinema (impressive work!).  Ongoing testing will include further analysis of the material, e.g. pH and mechanical strength measurements and fungal resistance tests.

While this was the first time I had heard about nanocellulose it has many potential uses, and not just for mending translucent materials. As a biomaterial derived from renewable forestry resources, nanocellulose has gotten a lot of attention over the past five years for its potential in industrial applications. Given its high ratio of strength to weight it has great potential for use in fill materials of all types, and has already found applications in industrial 3D printing as a substitute for carbon fibers in composites.  Since it is compatible with many adhesives, it may find wide-ranging applications in conservation. I am looking forward to hearing more about Remy’s ongoing research and thank him for the excellent introduction to an interesting material. You can learn more about Remy’s work at his website.

45th Annual Meeting – Objects Session, Wednesday 31 May 2017, “Archaeological Glass Conservation: Comparative approaches & practicalities of using acrylic resin films as gap fills” presented by Jan Cutajar and Hana Bristow

Jan Cutajar is Research Assistant at the University College of London, and Hana Bristow is Assistant Conservator at the National Museum of the Royal Navy, Portsmouth. They jointly presented on their experiences making acrylic resin fills with Paraloid B-72, an acrylic co-polymer, for use with glass repair. They based their work on techniques previously established by Steve Koob from the Corning Museum of Glass and recently updated at the CCI Symposium in 2011 (See here for the last update: https://www.cci-icc.gc.ca/discovercci-decouvriricc/PDFs/Paper%2035%20-%20Koob%20et%20al.%20-%20English.pdf).

 

Cutajar and Bristow treated two archaeological glass vessels: one Sassanian glass from UCL, and one beaker from Exeter, as case studies. They had common goals of needing reconstruction, stabilization, and the ability to be studied. They also had similar physical characteristics of degraded but stable glass with relatively good contact between the extant shards, thin walls (as thin as 0.2 mm), and substantive loss around of 35%.

Detail of resin fill in place on the Exeter glass jug (300/1988/G155, Royal Albert Memorial Museum, 2015). Photo by Hana Bristow

In looking for a fill system, they wanted a material that could reinforce weak areas, aid in practical assembly, and be as minimally interventive as possible. Since working with epoxy would require considerable manipulations with the artifact for both direct and indirect casting methods, this was not chosen. Instead, acrylic resin fills were explored because they are lightweight, strong, flexible, thin, detachable for future retreatment, simple to produce and insert, and can be manipulated for color and opacity matching.

Detail of resin tab application on Sassanid glass vessel (6300, UCL Conservation Teaching Collection, 2015), highlighted on the left and blended against the glass on the right. Photo by Jan Cutajar.

Koob’s technique is based on 30% w/v Paraloid B-72, an acrylic co-polymer, in acetone, with ethanol added to slow the evaporation rate, thereby reducing the potential for bubble formation. For coloring, ground pigment can be added to the ethanol before adding it to the resin mixture. The pigmented ethanol should be first decanted to prevent larger pigment particles from being added. The solution is cast and stored in a partially sealed environment for slow evaporation. Bristow felt that B-72 alone was too flexible, so she explored resin mixtures and tested varied proportions using B-72, B-48N or B-44 either straight or mixed in 2:1 ratios but always 30% in acetone. She also tested these opacifiers: fumed silica, marble dust, titanium dioxide and whiting. She cast the test resin mixtures in boxes of the same size, also holding the volume and concentration of the solution and the volume of added ethanol constant. The tests were evaluated after 4-5 days of curing for hardness, plasticity, and appearance. She found that a 2: 1 solution of B-72: B-48N produces a strong film without brittleness. This film was stronger than the B-72 film and not brittle like the B-48N alone or B-44 films.

The resin films are set to cure in a partially sealed solvent atmosphere. Photo by Hana Bristow.

For the opacifiers, Bristow found that fumed silica worked well for adding translucency, and marble for opacity, but whiting and titanium dioxide produced speckled results and were difficult to homogenize with the mixture. She also notes that dry artist pigments are good for tinting but shouldn’t be relied on for opacity as well, because they easily over saturate the mixture, resulting in a cracked and weakened cast. She recommends a maximum of 1.5 micro-spatula scoops per 30 mL resin mix.

 

Cutajar and Bristow offer some practical notes and tips:

  • Achieving desired film thickness can require some trial and error. Expect about 70% volume shrinkage.
  • Trays should be non-absorbent and easily release the resin. Making or using solvent-resistant boxes lined with release papers or films works well.
  • Enclose the poured resin trays in an acetone rich environment to slow the rate of evaporation. This will help prevent bubble formation.
  • Films should set for at least 4-5 days before removing, otherwise the films are too flimsy for these applications.
  • Films are best to manipulate directly after demolding. Things that can be done are:
    • Texturing
    • Shaping
    • Cutting – determine the size by taking a tracing of the loss area
  • Shape can be adjusted using heat; about 20 seconds under a hair dryer works well. Once warm, hold the cast in the desired position until it cools enough to hold the new shape. This can be done through repeated heating and cooling cycles until desired shape is achieved.
  • Adapt a cast by creating a lip at the edges where joins are very thin. This creates a slight overlap with the adjacent glass. The lip can be created with a heated spatula away from the glass.
  • Bonding can be activated with acetone, but Cutajar and Bristow suggest using more adhesive (Paraloid B-72) to make the join since acetone can compromise a good fit.
  • The film can be cut into tabs and used as reinforcements across joins. Cut the tabs into shape, lay them across the join, and activate with solvent. The tabs are virtually invisible.
  • The film can be used to make recessed fills for backing thin, curved glass, providing local stabilization and weight redistribution.
  • Backing films are easier to apply when they are freshly removed from the solvent atmosphere and retain a slight tack.

45th Annual Meeting – Objects Session, Wednesday 31 May 2017, “So Delicate, yet So Strong and Versatile: The Use of Paper in Objects Conservation” presented by Paula Artal-Isbrand

Paula Artal-Isbrand, Objects Conservator at the Worcester Art Museum, presented the various ways in which she uses paper in her objects treatments. She shared some background on paper types. Asian papers typically come from the paper mulberry tree and produce long fibers (kozo) and strong paper or from the gampi tree, producing shorter fibers to make crisp and translucent papers. Mitsumata shrubs are a third source, but not part of this presentation. Western papers are more often made from cotton, linen, flax, or hemp. Paper in conservation is strong, inert, compatible with conservation materials, has excellent long-term stability, and does not pose health risks. It can also be manipulated to mimic a wide range of materials through inpainting and coating. By choosing the right coating materials, the translucency and texture can be adjusted to fit the application. These papers can also be inpainted with standard inpainting materials to match color and texture.

Beaker, Roman, 3-5th century CE, glass, 15.5 x 7.0 x 6.5 cm. Sardis archaeological site (Turkey), Inv. # AhT67.IV.130N3,before and during treatment using kozo paper saturated with B-72 acrylic consolidant (Courtesy of Sardis Archaeological Excavation, photo: Paula Artal-Isbrand)

Artal-Isbrand outlined two ways for thinking about how to use paper. First, it can be used as a restoration material. Artal-Isbrand offered several examples of how she’s used paper in this way. For example, she used acid-free matboard cut into shape for a loss repair in a fan. For archaeological glass, she toned paper kozo paper with watercolors (not with acrylics since they would create too much opacity) and impregnated the paper with Paraloid B-72, acrylic co-polymer. The toned and resin soaked fill was a perfect match for the glass and was attached with Paraloid B-72. She has made paper fills to reconstruct chain mail, for joining heavy elements of an iron helmet, for reinforcing failing solder joins for bronze armor, and for backing a Roman lead curse tablet that needed to be unrolled. These repairs were carried out using a combination of kozo paper with Paraloid B-72, and are a testament to the paper’s strength. Artal-Isbrand also described that paper can be an interlayer between an artifact and fill material to ensure reversibility and how cellulose powder can be a bulking additive for fills, and if toasted, can also impart pigment to fills.

Missyurka turban helmet, Ottoman Empire or Caucasus, 16th century, iron, 29 x 18 x 18 cm. Worcester Art Museum, 2014.102. Bequest of John A. Higgins, during and after treatment with kozo paper strips. (Courtesy of Paula Artal-Isbrand)
Missyurka turban helmet, Ottoman Empire or Caucasus, 16th century, iron, 29 x 18 x 18 cm. Worcester Art Museum, 2014.102. Bequest of John A. Higgins, before, during (using kozo paper band-aids) and after treatment. (Courtesy of Paula Artal-Isbrand)

Second, paper can also be used as a tool. It can work well as a facing for an intermediate phase of treatment. It can also serve as a barrier layer. For example, thin papers are a great barrier film for gels. Here, Artal-Isbrand mentioned that thin gampi paper can be good for this. The paper is placed between the surface and the gel, allowing for easier clean up in gel removal. Paper can be a poultice material. Artal-Isbrand uses Whatman cellulose powder, which will cling well and hold the poultice solvent. For these same reasons, shredded filter paper soaked and blended in water can be used to create a mold of another artifact. The mold should be sealed with resin (for example, Paraloid B-72) to keep it from getting damaged by water applications. If using the mold for creating a plaster fill, this step is critical.

 

During the question / answer period, there was a brief discussion on how shredded paper serves well for poulticing, and is better than cellulose powder or other very fine materials, because those become difficult to remove and can leave a hazy residue. So, it is important to distinguish between powder and pulp or shredded and/or ground paper. An interleaving layer can be helpful if powder is used. Also during the discussion, another example was mentioned that paper can be rolled into “worms,” impregnated with Paraloid B-72, and inserted it into losses to provide filling that is more easily removed than putties or other fillers.

45th Annual Meeting – Research & Technical Studies, June 1, “Stability of Polyvinyl Butyral Polymers with Light Exposure” by David Thomas, Matthew Clarke, and Blythe McCarthy

Art from the Kizil Caves at the Smithsonian Freer Gallery of Art and Arthur M. Sackler Gallery

David Thomas and I could be career siblings. We both have technical backgrounds in materials and polymer science. We both spent time in industry. And this the first time for both of us at an annual AIC meeting. Add in my pre-conservation R&D work on adhesives and the photochemical reactions of polymers, and it’s not surprising that I was chomping at the bit to hear his talk “Stability of Polyvinyl Butyral Polymers with Light Exposure”.

David explained how he, Matthew Clarke, and Blythe McCarthy were looking at the possibility of using polyvinyl butyral (PVB) as an adhesive material for use in consolidating fragments of wall paintings from the Kizil Cave Complex in Xinjiang Province, China. These wall paintings are generally matte in appearance and are comprised of gypsum on mud plaster support. More specifically, sixteen fragile fragments had been leant to the Freer Gallery from the Smithsonian American Art Museum.

PVB was identified as a potential match to the consolidation needs of the wall painting fragments for a few reasons. It darkens to a matte surface comparable or better than similar materials, it is easily applied and removed using ethanol, and it has been shown to be an effective consolidant for wood and bone materials. This left the question: how does PVB age under light exposure?

Photo-aging of PVB might sound familiar. David pointed out that Robert Feller published results on the photodegradation of PVB materials in 2007 (http://www.sciencedirect.com/science/article/pii/S0141391005005057), digging into the chemical mechanisms of PVB degradation. The goal here, David emphasized, was not to look at the degradation mechanism itself but to investigate a more practical comparison of similar consolidation materials in actual use.

I found David at his most compelling when digging into the compositions and manufacturers of various grades of PVB. The types of PVB available vary primarily in their relative amounts of butyral, alcohol, and acetate content, a consequence of the polymer manufacturing process. He had a clear wealth of knowledge to offer here, and I wish he had presented even more (but that might just be the polymer scientist in me, your mileage may vary).

David and coworkers cast test films of a number of these grades of PVB, as well as control films of pure polyvinyl acetate (the industrial PVB precursor) and the ubiquitous Acryloid B-72 acrylic polymer, which were all then exposed to UVA (long wavelength UV) irradiation. At the same time, coworkers aged the same films by exposure to a weatherometer’s Xe lamp at the National Gallery of Art. They then tracked changes in color, mass loss, and IR spectra.

Trends in weight loss during aging of the films seemed to correspond with the polyvinyl alcohol content of the PVB: more alcohol led to more weight loss (ie, Mowital B30H degraded more quickly than Butvar B-98). The controls of B-72 and polyvinyl acetate showed no weight loss, and no appreciable discoloration. And by using a fiber optic-coupled FTIR to track the C=O carbonyl signal, an indicator of light-induced oxidative degradation, David showed that indeed the most rapidly degrading B30H showed increased C=O during aging compared to B-98, while the stable B-72 showed comparatively little C=O change and thus less degradation. In all cases, light-exposed PVB could be easily removed with ethanol, showing that no cross-linking reactions were occurring.

Comparison of chemistry induced by light sources as different as a weatherometer’s Xe arc lamp and comparatively narrow-band UVA lamp is a delicate affair. So I was disappointed that the talk did not include how the team evaluated light irradiance and dosage. It begs the question of how much photo-chemical energy was actually imparted to each sample. This also begged the question of heat. A Xe arc lamp in a small weatherometer chamber could reasonably be expected to induce a significant amount of heating compared to UVA bulbs. As David highlighted the comparatively high temperatures of Feller’s prior PVB work compared to the work presented here, it makes it difficult to determine how similar or different these varied results might be.

The data showing PVB applied and aged on Plaster of Paris mock-up materials looked promising. David offered some reasonable guesses as to why PVB might be more promising in real object application than on thin films. For example, more opaque materials would shield PVB from full light exposure by acting as a competitive absorber. And the color changes in PVB could be relatively minor compared to the colors of the treated object.

I still would have loved to have seen more about how closely the thin films and mock-ups behaved and had time to ask some of my more nagging questions about light and heat levels.

There are a few broader take-aways from David’s talk that I know I will be keeping in mind for myself:

  • It never hurts to take an extra look at the sourcing and composition of “trade name” products. As vague as they might be, a product’s MSDS/SDS could provide a useful starting point to sleuth out the components in new products or find changes in existing ones.
  • Mindfulness in equipment specs are crucial for useful comparisons of test cases. Perhaps even more crucial is carefully reporting those specs to simplify and aid others in their own comparisons.
  • Don’t take old studies at simple face value. David made a good case for trying them again closer to home and closer to your specific application of interest. You never know what you might find.

45th Annual Meeting – Textile Session, June 1, “Agarose, Two Ways: Successes and Challenges in Large Scale Gel Application” by Dana Goodin

The Textile Specialty Group audience got a real treat with Dana Goodin’s talk on using agarose gels on tapestries.  Dana, who works at the Textile Conservation Laboratory at the Cathedral of St. John the Divine in NYC, used agarose gel on two tapestries in two different ways.

The first was a Baumgarten tapestry dating to the 1910s.  It, and many others, were discovered on the walls of a townhouse on the Upper West Side of Manhattan after a developer purchased the property.  In previous years, the room the tapestries were in had been rented out as a studio apartment.  (As an NYC resident myself, you can only imagine the envy this inspired in me!)  The tapestries were attached to the wall around the perimeter with nails.  Stains from leeching plaster were prevalent and the lining had fallen down behind one tapestry, resulting in ballooning and a large slit at the bottom.  A square had even been cut out of a tapestry to access a utility box!  The tapestries were de-installed in 2013 and brought to the Lab, where there were laid flat in a humidity tent.  The humidity was maintained between 52% – 58% for many months.  This was not enough, however, to restore flexibility to the desiccated silk elements of the tapestry.  Since the silk in the tapestry was in such poor shape, it was feared it would disintegrate during wet cleaning.  It was therefore decided to clean, and of course humidify, the tapestries through agarose gel.  Dana told us that the Textile Conservation Lab would usually use a 1% density gel if the material were smooth and could later be rinsed under suction.  Because this was not an option with the silk, it was decided to also rinse the cleaned tapestry with agarose gel and deionized water.  For cleaning, 3.4% density gel, ¼” in thickness, was cast with Orvus.  The Orvus solution was 5ml to 300ml water.  The entire Baumgarten tapestry was cleaned with gel, although the wool elements received thicker gels and were rinsed under suction, rather than with gel.  The treatment was a great success: the appearance was incredibly improved and the tapestry regained enough moisture that it could afterwards be rolled without worry.

Clearly, this treatment required a lot of agarose gel, the cost of which escalated quickly.  Not to mention the time spent casting it.  Therefore, Dana and the other conservators at the Lab tried out reusing the gels.  Tests were performed on white China silk and it was found that after three rinses/soaks of the gels in Orvus, no soiling was redeposited on the test silk.  This was a great find, although it was concurrently found that the gels could only be reused three times before disintegrating.

The second tapestry Dana spoke about was an Agam tapestry from the 1970s.  It was made from white wool yarn and a variety of wool/synthetic colored yarns.  It suffered from hard glue residue on the top and bottom 2” of the tapestry, which previously attached a lining.  Complications arose from the fact that the red and black yarns bled.  The face of the tapestry was cleaned via dry surface sponging, but obviously that did nothing to address the glue, which was so hard it couldn’t be sewn through.  Tests showed that amyl acetate removed most of the glue.  Application methods tested were with blotters, cotton linters, and agarose gel.  The agarose gel proved the most effective.  Gauze was placed below the tapestry, then the gel was draped over the glue, before being weighted.  Although effective, this proved very time consuming.  To speed things up, Dana and the other conservators decided to apply the amyl acetate directly to the glue and then drape the gel over these sections with weights on top.  2% gel was used for this, and left on for one hour.  This process was repeated until as much glue was removed as possible.  The treated areas were rinsed with deionized water, and the tapestry received a new lining and a Velcro hanging mechanism.

I don’t think I’m overstating things by saying these were two awesome treatments.  Thanks for sharing them with us, Dana!

45th Annual Meeting, Book and Paper + RATS Session, May 31: “Contacts that Leave Traces: Investigations into the Contamination of Paper Surfaces from Handling,” by Karen van der Pal

In libraries, archives, and museums around the world, those in charge of protecting cultural heritage struggle with the topic: Gloves or No Gloves? Karin van der Pal’s talk on the contamination of paper surfaces from handling gives measurable data pertaining to the debate.

Van der Pal’s studies in forensic analysis are being conducted at Curtin University in Western Australia. She is currently collaborating with the Indianapolis Museum of Art on the chemistry of latent fingerprints and with Flinders University, in South Australia.

Van der Pal received paper samples from an Australian paper mill to conduct her research. She first solidified her own approach on how to not contaminate the papers she was testing: wearing cotton gloves underneath nitrile gloves she could take off the top layer and replace with a new set of gloves during the process without any of her marks coming through.

Historically, we know that dark fingerprints appear on paper. The edges of leaves in books become discolored as well. But is this a result of dirt, or could it be because of fingerprint oils? Van der Pal explained that the residue left by fingermarks include aqueous deposits, lipids, and dead skin. The proportion varies based on a person’s age, gender, and diet. Another variable on the kind of mark that is left is environmental exposure. If the pages with the contamination are left in the dark, there is little discoloration, but exposure to light causes the marks to darken.

Fingerprint deposits can be a combination of sebaceous oils and sweat from ecrine and apocrine glands. Typically, van der Pal explains that when a finger print is left, the oily sebaceous residue is on top, while amino acids sink into the paper, and the oil residue evaporates. In van der Pal’s experiments, the fingerprints are not visible to the naked eye, so it was necessary to apply an indicator agent that could show the intensity/saturation of the print left on her test papers. Ninhydrin has historically been used, that develops a fingerprint into a pink-purple. 1,2-Indandione/Zn Chloride exhibits color and luminescence and can show marks left up to 150 years old, so van der Pal selected this to use as an indicator.

The goal of the speaker’s most current experiments was to determine how effective hand washing is, if contaminants pass through gloves, and what effect hand gels and sanitizers have on papers. Using the 1,2 Indandione/Zn Chloride, van der Pal was able to determine that no contaminants come through nitrile gloves up to 2 hours. She cautioned that fingerprints and oils can still be picked up onto the outside of the nitrile gloves if one handles doorknobs and keyboards, for example. One also has to be mindful that wearing nitrile gloves for an extended amount of time is very unpleasant, so an option could be to wear cotton gloves underneath.

Van der Pal’s experiments show that 5 minutes after handwashing, the oils in the skin come back, and that 15 minutes after washing, there is more oil than prior to washing because the body is working to redevelop the oil lost.

Hand creams are left on the surface of the paper.

Antibacterial gels also do not prevent oils from being left on paper.

In the future van der Pal expects to study how drying/aging affects a wider range of paper, how long the fingermarks last on the paper, and what effects whether the marks darken.

Questions from the Floor:

Q1: Can you still detect marks on paper that have been washed? A1: Yes, you can still detect marks on paper that has been subsequently washed up to 3 months.

Q2: Regarding gels, how long did you wait until you tried to detect the oils? A2: we tested at different intervals of time.

Q3: Was there a transfer of the materials/paper to the gloves? A1: Reusing gloves can cause a transfer. Some gilding can attach to cotton gloves. Nitrile shouldn’t pick much up.

45th Annual Meeting – Textile Session, May 31, “Learning From Treatments That Did Not Go As Planned” by Suzan Meijer and Marjolein Koek

Involving a beautiful dress from the late 1860s and stunning before and after photos, Suzan Meijer’s talk was a definite crowd pleaser.  Her talk focused on a silk moire dress in the collection of the Rijksmuseum Amsterdam.  (Now on my Top Ten list of places to visit, as it has over 10,000 textiles, the largest collection in the Netherlands!)  Treatment of the dress was spurred on by the museum’s launch of an expanded website that would allow digital access to select objects in the collection.  This dress was selected because it is one of the few examples of the late 1860s pre-bustle period remaining unaltered.  However, its selection meant that it would have to be dressed on a mannequin for extensive photography.  The dress had been kept in hanging storage, covered, for decades, and Suzan spoke of the truly delicate condition it was in: the silk was split throughout the skirt, and shattered in many places across the bodice.   These damages far exceeded those outlined in the last condition report from 1950 (which may have been partially caused by the dress having been worn to a party at the museum in the early 20th century!).  Although wear and long-term hanging storage undoubtedly contributed to the poor condition of the dress, Suzan noted how the moire production process would also have contributed to the degradation of the silk.  Moire is produced through calendering, which involves heat and a lot of pressure.  Tests showed that the silk may further have been weighted slightly, as small amounts of aluminum and iron were found in the fibers.  But despite structural issues, the silk was phenomenally un-faded!  The dye came back from the lab as 50% barberry and 49% unknown purple, red, and violet components.  One could easily see why the museum was eager to have this dress appear on their website!

However, to make this possible, it was determined that the skirt had to receive a full lining, and that the full lining would have to be adhesive since the silk was so delicate.  Unusual for the period, the bodice and skirt of the dress were attached.  Suzan said they hoped to apply the adhesive lining without clipping any of the original stitches but that attempts soon proved this impossible, due to the tight cartridge pleating at the waist.  Therefore, the decision was made to remove the skirt from the waistband so it could be laid flat.  Evacon R, an EVA adhesive, was applied to silk crepeline.  The adhesive coated silk crepeline was then attached to the interior of the skirt using heat reactivation, between 65-75 degrees Celsius.  When this was completed and the skirt began to be re-pleated, it was noticed that some of the slits were popping.  To fix this, nylon net was used as an overlay along the top few inches, sewn down to the underlying silk crepeline.

As for the bodice, it lacked both boning and lining, which proved fortuitous when repairing the shattered silk.  As with the skirt, adhesive-coated crepeline was used, but rather than a full lining, patches were applied.  Again, net was used as an overlay and stitched through to the crepeline.  However, unlike the skirt, small areas of the silk were missing, rather than just split.  Toned Japanese paper was used to fill in these losses.  After the stunning photograph was taken, available here, it was time for the dress to go back into storage.  Obviously, hanging storage was no longer an option, so a large custom box was made in which the dress could be stored flat.  A small “shelf” and tray was built into the box to accommodate the separate belt.  Suzan says that how surprising the condition of the dress was when treatment commenced led them to re-think their hanging storage.  Covers were removed and the garments moved farther apart so that any downturn in their condition would be noticed immediately.  I wish I had before photos to truly illustrate the amazing transformation this dress underwent.  Good job, Suzan!

 

45th Annual Meeting- BPG Session, May 31, “The Codex Eyckensis (8th century). Re-evaluation of the 20th century restoration & conservation treatments by Lieve Watteeuw

Professor Lieve Watteeuw introduces her presentation with a description of the Codex Eyckensis, the subject of her talk. The Codex is comprised of two distinct gospels bound as one, most likely made at the scriptorium of Echternach in Luxembourg in the 8th century. A study in 1994 showed that both of the gospel manuscripts were made in the same scriptorium, and most likely by the same scribe. The manuscripts were held in the treasury of the Abbey of Aldeneik until they were transferred to the treasury of St. Catherine’s church in Maaseik in 1571 during a period of religious unrest. In 1596, a pilgrimage feast was arranged to honor the pilgrimage of the Codex and the other treasures from the Abbey of Aldeneik. Every 7 years thereafter, in tandem with the holy feasts of Aachen, the Codex would be on view, processed to its former home at Aldeneik.  The manuscripts were turned over to private ownership in the years following the French Revolution, until they were returned to Maaseik in 1871. From that date, the manuscripts were again part of processions, but only every 25 years.

from http://www.codexeyckensis.be/codex-eyckensis-the-unique-codex-of-eyke

It was observed in 1957 that the manuscripts were in very poor condition, so an attempt was made to preserve them. At the time, bookbinder Karl Sievers of Dusseldorf laminated the pages of the manuscript with Mipofolie, a polyvinyl chloride (PVC). In the late 1980s, Professor Watteeuw noticed that the leaves had suffered from this treatment. The PVC had turned yellow and had hardened, and it was decided to remove this damaging material.

The conservation treatment spanned from 1989-93. The removal of the mipofolie was accomplished using a technique developed in Budapest, which involved suction and a light table. Once the mipofolie had been removed, losses in the leaves were filled with parchment pulp. In removing the plastic foil, some pigment was removed as well. All of the mipofolie sheets were kept that had been removed from the Codex Eyckensis with the idea that they might be able to be used one day. At the time of this intervention, the curators decided to rebind the two distinct manuscripts separately using glue free bindings with deer skin covers over oak boards. The manuscripts were put on permanent display.

from http://www.codexeyckensis.be/codex-eyckensis-the-unique-codex-of-eyke

After years on permanent display, Professor Watteeuw was asked to perform a condition report of the Codex in 2008, and in 2016-17 she began the process of analyzing the manuscripts. Her studies showed that there was still residue of the PVC within the pores of the parchment. With the Hirox 3D microscope, parchment fibers from the leafcasting treatment could be seen overlapping into the pigment on the leaves as could Japanese paper fibers from paper mends. MA-XRF (macro x-ray fluorescence ) analysis demonstrated the presence of Cu, Fe, Pb, and Iron Gall Ink, suggesting important similarities to the pigments used in the Book of Kells. The MA-XRF also showed that the same palette was used for both of the manuscripts of the Codex Eyckensis. Watteeuw used photometric stereo to document the thickness of the paint layers along with their texture. Using the pigments peeled away from the manuscript leaves on the mipofolie foils, Watteeuw could analyze the pigments using Raman, essentially making the best of a bad situation set in motion when the mipofolie was applied in 1957.

All of this analysis gives information on the possibly very close connections between the manuscripts of the Low Countries to Anglo Saxon lands. During this analysis,  Professor Watteeuw also played a crucial role in digitizing the Codex, which is now available online.

Questions from the floor following the talk:

Q1: Were you able to ID the green pigments? Can you see corrosion? A1: yes we were able to see corrosion, but undetermined green pigment, since some green not corroded.

Q2: Was there treatment strategy of stabilizing copper green? A2: no consolidation in the 90s, but parchment pulp might not have been the best choice of fill material (could have made worse?) Watteeuw notes she is afraid to turn the pages because she can hear the PVC within the leaves.

Q3: Any underdrawing? A1: yes, underdrawing or “mise en place” of canon tables is visible

Q4: Is it on permanent display? A4: yes, was on permanent display at fixed page. Now it’s in the lab, but will eventually be on permanent display again, for which we are developing lighting scenarios.

What a great, informative talk! Thanks to Professor Watteeuw, and I look forward to seeing what more they discover about these incredibly important manuscripts!

 

Bibliography

https://www.arts.kuleuven.be/english/news/codex_eyckensis

http://codexeyckensis.blogspot.com/

http://www.codexeyckensis.be/codex-eyckensis-the-unique-codex-of-eyke

45th Annual Meeting – General Session, May 31, “Not a Known Carcinogen: Health and Safety Considerations of New and Innovative Treatments” by Kerith Koss Schrager, Anne Kingery Schwartz, and Julie Sobelman

As conservators, we routinely use a host of chemicals, sometimes in ways that are unusual. As a result, it is important for us to take proper precautions at all times. However, as objects conservator Kerith Koss Schrager and industrial hygienist Julie Sobelman pointed out at this year’s annual meeting, we may not always do so. Since we are used to solving complex problems, we do not always seek out health and safety experts to interpret for us, even though they may be required. Much of our behavior around health and safety is learned by example, and we may make judgments based on personal experience. While we are always taught to prioritize the safety of the objects we treat, we may not always prioritize our own safety in the same way.

Kerith and Julie illustrated these issues using the example of cyclododecane. Cyclododecane is used in multiple areas of conservation, and while there are over 100 conservation publications mentioning it, few of these mention health and safety concerns. Most of conservators’ information about the chemical comes from the safety data sheet (SDS), which suggests that it is not hazardous. A survey of conservators found that roughly half of those surveyed did not believe it was safe, while 18% believed it was. The respondents based their answers on either the SDS or on hearing of other conservators using it. However, the SDS for cyclododecane is based on industrial use of the chemical, which is very different from the way conservators use it. In the case of cyclododecane, research is conflicting as to whether it is hazardous.

Rather than looking at just the SDS for a chemical before using it, Julie suggested consulting additional resources such as EPA Chemview and CDC/NIOSH International Chemical Safety Cards. If we have to use chemicals about which we are uncertain, using proper environmental controls and other protective equipment is important: using a fume hood does reduce exposure.

Julie and Kerith ended their presentation with a plea for conservators to create a culture where health and safety matters. As a newly fledged conservator who does oversee interns and volunteers, I left the room committed to making sure that those who share my lab have no reason to regret doing so.