BethEdelstein – AIC Blog Archives: Conservators Converse

44th Annual Meeting – Research and Technical Studies, May 17, "Binders and pigments used in traditional Aboriginal bark paintings” by Narayan Khandekar

This was the last talk I saw at the meeting and was a perfect way to wrap things up, with a travelogue-slash-fascinating research project on the materials and techniques of Aboriginal paintings from the northern part of Australia. Narayan traveled to various art centers and museums to look at and sample pre-1960s paintings, talk to artists and gather local materials. He took about 200 samples from 50 paintings (including some from Harvard’s collection), the oldest from circa 1878. He also obtained materials from artists working today, some of whom took him around to gather materials from local sources, including the beaches of Bathurst Island (part of the Tiwi Islands off the coast of the Northern Territories – thanks Google Maps!). Back at Harvard, he and his colleagues (co authors were Katherine Eremin, Daniel P. Kirby & Georgina Rayner) gathered information on pigments, binders and other materials present that may indicate previous treatments. Narayan pointed out that only two samples of similar paintings had been analyzed and published before, such that this study presents entirely new information.

Of particular interest was the investigation into possible binders. Oral histories and documentary evidence recorded various possible binders, including turtle eggs and orchid mucilage, but it was generally thought that paintings made before the arrival of missionaries in the 1920s didn’t have binders at all (a similar question has been on my mind regarding the paintings made in the Sepik River region of Papua New Guinea). Binders were present in 77% of the samples analyzed. No proteins, waxes, fats or blood were detected. The analysis of the oldest paintings did reveal the presence of orchid juice, confirming that binders were in use that early. The techniques of using orchid mucilage could vary; the sticky juice could be mixed with the pigment, or laid down first before applying the pigments mixed in water.
As expected the pigments were largely ochres, and Narayan noted that the trace elements present in the samples provide a fingerprint that can in theory be used to begin to trace the occurrence of different ochres in different areas, but that more study and sampling is necessary to pursue this.

Other interesting findings included the use of dry cell batteries as a source for black manganese and zinc pigments on paintings from Groote Eylandt (yes a very great big island off the east coast of the Northern Territories); this area also shows the use of natural manganese-rich ores and charcoal for black pigments. A curious silver oil-resin paint on two paintings from the 1920s turned out to correlate with the roof repainting of a nearby lighthouse at the same time. The presence of DMP (dimethyl phthalate) in some paintings prior to 1957 resulted from the liberal use of insect repellent (FYI this is the main ingredient in Avon’s Skin-so-Soft; it fell out of use when DEET was invented). The presence of nitrocellulose on Groote Eylandt paintings was connected to records from the 1948 expedition suggesting that they had been consolidated with Duco.
As always, research continues, and Narayan mentioned that they would be looking further into the use of gums and of bloodwood, though I didn’t get down any details on that (I hadn’t actually planned to blog the talk, so apologies for any lacunae!). Also, I’m pretty sure there was a crocodile sighting mentioned, but that too didn’t make it into my notes, so here’s one of my favorites for good measure…

44th Annual Meeting – Collection Care Session, May 15, "Spoiler alert! Planning around the pitfalls of construction projects" by Jeffrey Hirsch and Angela Matchica

Construction projects have been on my mind lately and I thought this would be a good complement to Angela Chang’s presentation about her experiences during two major construction projects at the Straus Center (she spoke at the Conservation & Exhibition Planning: Material Testing for Design, Display, and Packing conference in DC in November 2015). Jeffrey Hirsch and Angela Matchica from Ewing Cole (an architect-design-engineering-planning firm) put together a clear and useful review of how conservators and collections care professionals can be active participants in a construction planning process. They took turns speaking, with Jeffrey giving an overview of each issue or area of collaboration, and Angela providing the in-practice examples from her experience as a lighting designer. The concrete examples were helpful in illuminating how collaboration goals can be translated into actual practice and decision making.
Jeffrey emphasized the complexity of the team on both sides of a museum construction project, with a wide variety of interests being represented. He noted that while those from Facilities departments are probably used to talking to architects and designers, the rest of the museum representatives may not initially be as comfortable, but need to make the time to stay at the table and speak up whenever they have questions. The slide below started out as just two dots – Design Team and Museum – and then grew and grew to encompass all the different roles that are part of the discussions around planning a new space or changes to an existing space.

In this diverse group, achieving consensus can be difficult, and knowing everyone’s individual needs is important. Angela discussed one instance in which repaired dinosaur skeletons were going on view, and light levels were initially assessed for the bones themselves, though it turned out that the most sensitive material present was the adhesive in the repairs. She also mentioned that they built a standalone mockup so that lighting levels could be experienced by all stakeholders, to get a real sense of what the space would feel like with different lighting, to achieve consensus. I thought this slide was helpful in illustrating all the sub-questions from different stakeholders that are a part of one major design decision.

Jeffrey noted that what looks like one construction project is really a number of simultaneous and interdependent projects – structural, exhibit design, conservation, and so on – all coming out of basically one pot of money. Scheduling all of this was likened to a symphony, in which it’s very difficult to get the multiple instruments to finish the piece at the same time.

As always, communication was underscored as the most essential element. Each group should be aware of how the other groups are progressing, and know if someone’s end date is shifting, and what that means for all the others. On this point, he stressed how important it was to have a contingency amount of funds specified in the budget very early on. Changes cost a lot more at the end then they do at the beginning, so it’s also important to assess all your options early on and make choices then, with full information about the long-term costs of each option. Here, Angela presented the choices between various types of light bulbs, some of which are low cost but require frequent replacement, while spending a bit more at the beginning can lead to major savings in time and materials later in the life of the building – value engineering.

The end message for all involved parties was to stay at the table, attend all meetings, read and familiarize yourself with all the minutes and notes, and keep track of what decisions are made. No sweat! I still feel like the only way to really know how to predict and prepare for all the things that can go wrong in a construction project is to go through one and learn from your own mistakes – but it was great to hear from the other side of the table, especially from a team that has a real sense of the wide-ranging and diverse concerns of working in a museum setting and the energy to work towards collaboration.

AIC’s 40th Annual Meeting – Architecture Session, May 10, “Interior Murals, The Conservators Perspective: Access and Experience of the Conservator within the Architectural Space” by Gillian Randell

Gillian (with a hard “G”) is a conservator of interior murals and decorative finishes and presented beautiful images of a wide variety of 18th and 19th century American murals, with a deep appreciation of the special perspective of the conservator, given our unique level of access to these artworks. She began by relating this level of access to her experiences spelunking and finding herself in close proximity to spaces and places most people don’t ordinarily see – Werner Herzog’s 3d film of the caves of Chauvet came into the conversation here, with its attempt to give wider audiences that feeling of close contact, discovery, and the sense of actually being there.

American interior decoration of the 18th and 19th centuries is characterized by extensive interior painting. One of the artists Gillian focused on today was Edwin Howland Blashfield, who painted murals in both civic and ecclesiastical venues and had a particular technique of using rich layering on a monumental scale, producing a range of textures. In these murals, the distance of the viewer encourages the use of trompe l’oeil and other effects, which also have a significant impact when viewed up close. Blashfield was friends with Francis Davis Millet, another progressive muralist, and was a member of the group that founded the Mural Society of America in 1895. Many murals were produced as part of the “City Beautiful” movement, which promoted “beauty not only for its own sake, but also to create moral and civic virtue among urban populations.” Many neoclassical murals in public buildings were produced at this time, including Blashfield’s Power of Law in the Manhattan Appellate Courthouse, which was conserved in 2005 and is part of a mural cycle produced with other mural artists.

We moved next to the Essex County Courthouse where muralists Lowe, Walker, Turner, Cox and Blashfield painted a series of pendentives around the domes – Gillian noted that these were painted with extensive and subtle detail, even though it wasn’t necessary as they were viewed from a distance. These were cleaned in 2004 so the photo in the link above shows them rather at a worse phase in their lives…for better ones, look on Evergreene’s website.

St Matthew’s Cathedral in DC boasts a series of lunettes, painted in Blashfield’s studio and then installed afterwards, with more painting on site to integrate them. Here he used what was termed “percussive brushwork” (I don’t know where the term came from) using a large brush to “hammer” paint onto the surfaces, creating texture and movement. This was cleaned in 2003, removing surface dirt and grime. There was also apparently an early synthetic surface coating on these murals, which was analyzed at CCI; the murals are painted in oil on linen.

The Assembly Chambers in Albany NY display murals on stone by William Morris Hunt, which were partly covered by a ceiling installed less than ten years later. The mural “The Flight of Night” dates to 1878, a year before Hunt died in 1879; another is “The Discoverer”, dating also to 1878. He had produced many preparatory drawings and paintings as he had been working on this theme for decades; these as well as related 3d clay and plaster studies are in various museum collections. These paintings suffered from roof leaks, damage to the sandstone, salt formation, and most of all the use of paint materials incompatible with the substrate. Hunt may have been using “experimental” materials – he referred to a “secret recipe”. It seems that he was working in an oil-based medium. However, he did not put any preparation layer on the stone such that even while he was working, he noted that the stone absorbed the paint, leaving a more faded appearance the next day – in our terms, the stone had absorbed much of the oil binder, leaving a very underbound layer and precluding the formation of a stable oil film. Because of this “fading”, Hunt applied paint in multiple applications, but the underbound layers continued to fade and degrade over time.

At Rockefeller Center, the wall where Diego Rivera had painted his controversial mural (the one with Lenin), which was demolished in 1933, continued to cause problems with the replacement mural, called “American Progress” by José María Sert – problems which the conservators called “Rivera’s Revenge”. Here’s an NYTimes article about the conservation work there.

Because the architecture session had begun about twenty minutes late (the business meeting ran over) Gillian had to start to run through her remaining slides quickly at about this point. We saw Ezra Winter’s Fountain of Youth mural at Radio City Music Hall, and some wallpaper in the bathroom there designed by Donald Deskey, who was responsible for all the interior decoration of this building. We then sped over to the Pantheon de la Guerre at the National WWI Museum at Liberty Memorial in Kansas City, which is a cyclorama of WWI heroes which was painted in France and presented at the Chicago 1933-34 World’s Fair, then toured around the US (currently the subject of an exhibition). It was 402 feet long and 42 feet high. After the tour, the mural was largely forgotten and stored outdoors until Baltimore restaurateur William Haussner bought it at auction in 1953. In 1957, Kansas City artist Daniel MacMorris persuaded Haussner to donate the panorama to the Liberty Memorial Association, which acquired it with the okay to alter it to fit a new space; MacMorris “revised” it, cutting and pasting and adding more heroes. The last place we got to visit was Conception Abbey in Missouri, though I can’t tell you much more about that.

Looking up some of these sites online, I realize even more that it was a rare treat to see Gillian’s beautiful photos (I think she credited Whitney Cox with much of the photography) – there aren’t many images of many of these important works available, though often the Evergreene website has the best ones. Maybe some of the great images used in the presentation should be put online!

AIC’s 40th Annual Meeting – Architecture Session, May 10, “Preservation of Outdoor Public Murals: Research and Public Outreach” by Amanda Norbutus

Amanda Norbutus is in the Preservation Studies doctoral program at the University of Delaware, and has her undergraduate and master’s degrees in chemistry. Her presentation first outlined the state of public murals preservation and the issues faced today, then described current research into protective coatings for public murals and discussed a case study of a mural by Meg Saligman in Philadelphia that has been successfully treated.

The “Contemporary Mural Movement” refers to public murals produced since the 1960s (see cool book) and Amanda noted that there are more than 350 public art programs across the US that have facilitated the production of these murals. The murals often address themes of heritage and social and political equality. Loss and damage are rampant for a number of reasons: the murals are often spontaneous, not planned with long term preservation in mind; they are subject to extreme outdoor conditions; and they suffer from a lack of funding – while money is pledged for their production, none is usually allocated for preservation. The murals often also fall under various jurisdictional disputes – no one is quite sure who is responsible, or who has the right to make decisions about the wall or the image. To address some of these issues, Heritage Preservation has a program called Rescue Public Murals which carries out identification, documentation and conservation of murals, provides a network for those working on their preservation and researching best practice for mural production and conservation, and conducts fundraising (you can sign up here to get on RPM’s mailing list). They also have a partnership with ARTstor Digital Library to preserve images of murals, as not all can be physically preserved; there is a Community Murals collection in ARTStor. Amanda noted one prominent case in which Ken Twitchell, an artist who had painted a mural (Homage to Ed Ruscha) on a federal government-owned downtown LA building, received a $1.1 million settlement after the mural had been painted over.

A few of the biggest problems facing murals are graffiti, physical destruction, and desaturation as the paint layers weather and are exposed to UV. UV radiation causes cracking, color change and fading. Oxidation chain reactions are the culprit on a chemical level. Research has been ongoing to look into protective UV barrier coatings. Some limitations are – scale, access, acceptability by stakeholders, safety (VOC’s), and ease of application. Some of the categories examined include acrylics, waxes, polyurethanes, and silanes.

In a study that began in 2005 at Delaware, Jessica Keister painted out more than 700 samples of blue, yellow and red colors of various types of paints from Golden, Novacolor, and Keim, in addition to some fluorescent colors. As coatings, she looked at B72 with Tinuvin, Novacolor, Golden MSA varnish, and a Triangle Triton coating (not reversible). The samples were placed on the roof and exposed to weather for three years. In 2008, Amanda began looking at the samples, noting the differences between colors – Hansa yellows did best – and paint systems – Golden heavy bodied acrylics did best. Golden MSA varnish seemed to protect the samples best – the Triangle coating was better at keeping mold and dirt off the surface, but its irreversiblity deducted crucial points from its usefulness. There was some success with B72 and Tinuvin (UV stabilizer), and in general two coats worked best of the protective layers. Amanda noted that products commercially sold as UV protective are not always so – she cited a test done by muralist Ed Massey on an industrial polymer coating that was purported to have a UV stabilizer, which failed completely. Finally, there needs to be more research into reversibility on a practical level, whether coatings can be effectively removed without affecting damaged paint beneath. Here’s more detail from Amanda about the parameters of the samples on an RPM blog post from 2008.

The Meg Saligman mural in Philadelphia is called Common Threads (1998), and when RPM assessed it in 2009 it was extremely faded. The artist didn’t want to repaint it, as she felt she would change it too much. Together with RPM and Winterthur Art Conservation faculty and students, the artist agreed to apply a coating of Golden MSA – but they had to get an exception from the EPA to use it on such a large scale. Applied after surface cleaning, this coating resaturated the colors significantly. They also then did some retinting with Sher-Cryl (Sherwin williams acrylic) and pigments (envirotint?) over the coating, then applied another layer of the Golden coating.

A key point is to work with muralists to prevent some of these problems from the get-go. Amanda noted that when doing this it’s important to address the bottom line – money – and emphasize that in the long run it is cheaper to use better products first rather than having to repaint or conserve a mural later.

She ended with a summary of other key points to remember when working with murals/muralists:

Get involved with the community
North facing walls are best
Clean and prime the wall first (amazing but often not done!)
Choose the right palette – no fluorescents, they fade fast!
Use quality paints
Use a coating layers
Use a UV absorber
Create a maintenance and monitoring plan
Consult with conservators and scientists when in doubt

Outreach Session on K-12 Education – next Thursday at 2:30!

We’ve lined up a great panel of conservators, two local teachers and the Director of Education at the Georgia O’Keeffe Museum to discuss how conservators can make an impact on K-12 audiences. As co-chairs of the AIC K-12 Working Group, we wanted to share a bit more with you about what we’ll be talking about and doing in this session than we were able to share in the conference program. We feel strongly that not only is it a lot of fun to work with elementary, middle and high school kids, but it gives us conservators a great chance to broaden their interests in art and in the sciences, and promotes value for our shared cultural heritage. What kid can’t tell you how acid rain is hurting the environment? Why shouldn’t they also be able to tell you what it’s doing to outdoor sculpture?

In this panel we’re going to focus mostly on the practical questions – what kinds of conservation-based topics translate well to these students? Who exactly is your audience and where will you encounter them – in your studio, in a gallery, in the classroom? How do you make inroads into your local schools, and find out who makes the decisions on what to teach? And how on earth do you fit this into your already busy work life? We’ll hear from conservators who have established tremendously successful programs, and hear directly from teachers and museum educators how they work – or would like to work – with conservators.

Then we’ll break up into focus groups, each one taking on a different age group (K-4, 5-8, and 9-12) and come up with some great ideas for topics, hands-on activities, and related explorations into other subject areas like history, social studies or math, so teachers can integrate these ideas across their school’s curriculum. These ideas will be further developed by the K-12 Working Group (and any interested volunteers, hint hint!) and be made available as lesson plans for conservators to take into their local schools, or for educators to use as springboards for working with conservators. The possibilities are wide open and we are excited to have a great and productive session. Please join us!

Details: Conservation and Education 1 Outreach Session, Thursday May 10th, 2:30-4, in Picuris/Santa Ana/Sandia