Specialties – Page 25 – AIC Blog Archives: Conservators Converse

42nd Annual Meeting, Objects Session, May 31, Pine Pitch: New Treatment Protocols for a Brittle and Crumbly Conservation Problem by Nancy Odegaard, et al.

In this paper presented at Saturday’s Objects Session, Nancy Odegaard, Marilen Pool and Christina Bisulca described a new treatment protocol they established, along with their colleagues Brunella Santarelli, Madeleine Neiman, and Gina Watkinson, for treating baskets with deteriorated, pine pitch coatings. The treatment protocol was devised after conducting a survey of the basket collection at Arizona State Museum, where the majority of the pitch-coated ethnographic baskets (70 out of about 100) had unstable, blanched, cracked and brittle surfaces. The baskets required treatment so that they could be moved to a new location.

The majority of the baskets were Apache and were made using a twining or coiling technique. The pine pitch, obtained from the piñon pine would have been applied to the surface of the baskets as a waterproofing measure. Two colors of pitch were observed on the exterior of the baskets, each with different condition issues. Some baskets were covered with a red pitch that appeared translucent. The other baskets were covered with a dark brown to black, opaque pitch. Both colors of pitch had suffered degradation due to factors such as UV, temperature and pollutants, however the red pitch appeared more unstable and had a formed a series of fine cracks. The darker pitch had deeper cracks.
Because the baskets had to be moved, a treatment protocol was established to stabilize the surfaces so the baskets could be safely transported to a new storage area. Previous treatments for deteriorated pitch had included consolidation with solvents or the use of heat (using a butane torch!) to reintegrate the cracked, crumbly surface. The ASM team was looking for another treatment option, and one that took into consideration the vast numbers of objects that required treatment. Borrowing from methods used to clean aged varnish in the field of paintings conservation, the conservators decided to reactivate the pitch using a solvent to stabilize the flaking material and reattach the crumbly surfaces.
Prior to any treatment, the conservators wanted to get a cultural perspective on the treatment since they did not want to add material, alter the pitch or appearance of the basket and wanted to make sure the objected retain their cultural integrity and significance. Nancy consulted with a Navajo weaver who said that pitch baskets should always look shiny and therefore reactivating the pitch, and the subsequent shiny appearance the material would take, was acceptable.
Treatment
Because of the success in the use of ethanol in cleaning aged, pine-based varnish from paintings, that was the solvent chosen for the reactivation of the pine pitch on the ethnographic baskets.

The first stage of the treatment was to place the baskets (many supported by foam rings or, if they fit, by large glass beakers) in an ethanol solvent chamber for 24 hours. This would condition the surface and prepare it for further treatment.
The baskets were then removed from the solvent chamber and areas of the surface sprayed with ethanol using a Dahlia sprayer for a more direct application of the solvent.
Brushes, foam swabs wrapped in PTFE (Teflon) tape and Kim Wipes (lint-free wipes) soaked in ethanol were then used to relocate any loose flakes.
After one side was treated, the pitch was left to air dry for a few hours, then the basket was turned and the other side sprayed with ethanol and flakes reattached.
When the entire pitch surface had been treated, the basket was left to air dry for about 24 hours or until the pitch no longer felt tacky.

During treatment the conservators noticed that the transparent red pitch reacted faster to the ethanol. The darker pitch was less soluble and more pressure was needed to re-adhere fragments. They also noticed that for areas with damaged basketry elements, the reactivated pitch served to reinforce those areas of the plant fiber so that no further stabilization of those woven elements were required.
Analytical Investigations
In addition to the treatment, instrumental analysis was conducted to characterize the two types of pitch and determine if there were any changes in the pitch before and after treatment. The analysis was conducted using Fourier Transform Infrared Spectroscopy (FTIR) and optical microscopy.
The first investigations looked at the two types of pitch and whether there were any changes observed before and after treatment. Analysis showed that there were no differences before and after treatment and therefore reactivation and exposure to ethanol did not alter the material chemically. There were differences, however, noted between the red and dark pine pitch. The transparent red pitch had a low aromatic component as opposed to the dark brown-black material, which had a high aromatic hydrocarbon content.
A series of experiments were then conducted in order to figure out what accounts for these differences and it turns out it has to due with how clean the pine pitch is and at what temperature it was initially heated to during application. Using optical microscopy, the dark pitch seemed to contain woody materials and had inclusions of bark. Could this be the explanation for the differences in the aromatic content?
Samples of resin from piñon pines in the Navajo area were collected and heated to different temperatures and then examined using microscopy as well as FTIR. It turns out that if the pitch is clean and does not contain any woody components, there are little to no aromatics. However, when bark is present in the pitch, the aromatic content is similar to that seen on the pitch coating the ethnographic baskets. The heating temperature also plays a role not only in the color, and a temperature of 180° C produces pitch similar to that seen on the ASM baskets.

This was a really informative talk describing a new approach to not only the treatment of crumbly pine pitch, but also a protocol for treating large numbers of unstable baskets. The talk was of particular interest to me because some close colleagues and I have often encountered similar types of condition issues with different resinous materials on archaeological objects (for example bitumen coatings on ceramics, bitumen or pitch on baskets, natural resins on Egyptian funerary objects and mummies) and have often discussed the need for approaches to the stabilization of these materials other than consolidation using synthetic resins. The literature is a bit lacking in terms of the treatment of these types of materials and it’s wonderful that Nancy and her team at ASM are adding to this body of information by sharing their treatment methods and findings (and hopefully publishing them in the OSG Postprints or another publication!).
The next stage of the pine pitch/basketry project will be to work on the archaeological basketry collection and I looked forward to hearing about their approaches to the stabilization of pitch on those artifacts.

42nd Annual Meeting – Paintings Session, May 29, "Eclectic Materials and Techniques of American Painters: 1860-1910" by Lance Mayer and Gay Myers

Gay Myers, with the support of Lance Mayer, presented research on American artists gathered from primary sources including artists’ interviews, notebooks, letters, manuals, and suppliers’ catalogues, periodicals, and advertisements. Their presentation focused on a period when more Americans began traveling to Europe.
The influence of instruction from French academics like Thomas Couture (1815-1879) was particularly strong. The American painter Elizabeth Boott (1846-1888) wrote manuscripts about European techniques that delineated Couture’s studio instruction in Paris, William Morris Hunt’s (1824-1879) classes in Boston, and Frank Duveneck’s (1848-1919) practice in Munich. Couture advocated the method of painting thinly over brown underlayers (these paint layers become more transparent over time, and so, this method has sometimes led to problems). He influenced several nineteenth century American painters including Eastman Johnson (1824-1906), Winslow Homer (1836-1910), and Thomas Eakins (1844-1916). Hunt and his pupil Helen Knowlton (1832-1918) believed that caring too much about one’s technique was stifling. Duveneck employed large amounts of oil media in his paintings to achieve a “buttery” application and sealed his works with extremely glossy varnishes. Duveneck’s varnishes were so thick that the American painter John Singer Sargent (1856-1925), who preferred light varnishes, advised others not to let “D” or any of his boys varnish their paintings.
The Art Amateur (1879–1903), an American magazine edited by Montague Marks (1847-1905), used the artists’ advice columns to document Thomas Dewing’s (1851-1938) use of matte varnishes, the growing popularity of the shellac-based Soehnée’s varnish as both a retouching and final varnish, and the early beginnings of the tempera revival in America. The American author Albert Abendschein (1860-1914) was among those in opposition to the tempura revival and has been quoted stating “the egg is more useful taken internally and kept out of the studio.” Abendschein instead advocated for indirect painting in which glazes are layered onto a monochromatic underpainting. In his 1906 book, The Secret of the Old Masters, Abendschein documented the growing tempura revival, commercially-produced paints containing wax, as well as other art trends.
J.G. Vibert (1840-1902), Edward Dufner (1872-1957), Mary Louise McLoughlin (1847-1939), and other significant members of the art community discussed varnishing practices, pigments, added media, and supplementary topics in a series of interviews conducted by DeWitt McClellan Lockman (1870-1957). The French author Vibert advocated a preference for petroleum solvents, and similarly, the American artist Dufner began using kerosene oil instead of turpentine because it dries without a glossy sheen. Dufner considered glossy surfaces so undesirable that he wrote on the verso of one of his paintings: “This picture being in a light key is meant to be matte surface and should never be varnished.” Vibert was also a staunch believer that lead white was not compatible with vermillion or cadmium and offered zinc white as an alternative. Concern about the toxicity of lead white also lead many artists, including McLoughlin, to start using zinc white. Since that time, technical analysis has confirmed zinc white is more prone to cracking than lead white.
This presentation effectively demonstrated the extent to which American painters experimented during the late nineteenth and early twentieth centuries. If you would like to learn more about the materials and techniques of American painters, Mayer and Myers have authored multiple publications including American Painters on Technique: The Colonial Period to 1860 (2011) and American Painters on Technique: 1860-1945 (2013).

About the Speakers
Lance Mayer and Gay Myers graduated from the Oberlin College conservation program (1977 and 1978) and work as independent conservators to private collectors and public institutions including the Lyman Allyn Art Museum. The authors are fellows of the American Institute for Conservation of Historic and Artistic Works (AIC) and have each served as chair of the AIC Paintings Specialty Group. They have collaborated on conservation and research projects for over thirty years, were awarded the Winterthur Advanced Research Fellowship (1999), Museum Scholars at the Getty Research Institute (2003), and College Art Association/Heritage Preservation Award for Distinction and Scholarship in Conservation (2013).

42nd Annual Meeting – Photographic Materials, May 31, "László Moholy-Nagy: Characterization of his Photographic Work at the Art Institute of Chicago and his Working Practices" by Mirasol Estrada

Mirasol Estrada, the Andrew W. Mellow Fellow in Photograph Conservation at the Art Institute of Chicago, studied the work of László Moholy-Nagy in the museum’s collection for two years. Her talk was a comprehensive look at the photographer’s working practices as well as the specific characteristics of his photographs in the collection at the Art Institute of Chicago. Ms. Estrada was drawn to the work of Moholy-Nagy because of the experimental nature of his working practices, and his philosophy of photography.
Moholy-Nagy always thought of himself as a painter but he also produced drawings, film and photographs. He came to Chicago in 1937 to direct the New Bauhaus, which then became the Institute of Design. He was an influential teacher, including teaching his philosophy about the practice of photography, published in his book “Vision in Motion”. This philosophy was summarized very nicely by Mirasol, who described Moholy-Nagy’s idea that there are eight varieties of seeing.
The first variety of seeing is “Abstract”, which includes photograms, which are direct records of shapes and shadows. The second is “Exact”, which is straight-forward camera photography. The next is “Rapid”, which shows motion, followed by “Slow”, his description for long exposures. “Intensified” was using chemical manipulation such as solarization. “Penetrative” described x-rays, “Simultaneous” was the term for his photomontages, and lastly, “Distorted” was the term for mechanical or chemical manipulation of a print or negative. This was an interesting summary of Moholy-Nagy’s ideas about the variety of seeing correlated to his photographic method – a good window into the photographer’s thinking process and the categorization of his themes.
Ms. Estrada then took us through the characterization, both physical and analytical, of the thirty-nine photographs in the Art Institute’s collection. She grouped the prints physically by their size, tonal range, surface texture, finishing (coatings) and thickness. These groupings were displayed in a very clear, easy to read chart detailing the characteristics, including thumbnail photos of each object overall and in detail to show tone, surface texture, etc. Analytical data for each object was also included (XRF, FTIR) to complement her visual observations. Using her chart, one could compare the date clearly and easily, looking at tone, texture, and subject of the image.
A few interesting observations that were made following the study were that Moholy-Nagy most likely did not process his own photographs – he has been known to have explained that he was allergic to the development chemicals. This may explain the diverse body of work and materials choices, since his students, wife, and daughter may all have been a part of the processing of his artwork. Moholy-Nagy used many different types of paper and other materials, especially noticeable on his move from Europe to the US, reflecting the marketplace at each time and place. Ms. Estrada offers that it was perhaps more important for the artist to express his ideas, his complex categories of “varieties of seeing”, in the Bauhaus tradition, instead of focusing on the fabrication of his artwork.

42nd Annual Meeting- OSG, May 31, "Restoration by Other Means: CT scanning and 3D Computer Modeling for the Re-Restoration of a Previously Restored Skull from the Magdalenian Era by J.P. Brown and Robert D. Martin"

After collaborating with JP at the Field Museum on rendering CT scans a few years ago and seeing his article about this work in the spring MRCG newsletter, I was excited to see some images about this in person. JP has been working with CT scanners since 2006 starting out by taking advantage of the kindness of local hospitals and more recently renting a portable unit that came to museum on a truck.
As many of us know, CT scanners can look inside objects non-destructively and provide accurate images with 3D geometric accuracy. JP started the talk be reviewing some of the physics of getting a CT scan done, the benefits, and limitations. Here’s a run-down:
1. The scanner has a donut shaped gantry consisting of a steel ring containing the X-ray tube and curved detector on the opposite side, so your object has to fit within the imaging area inside the steel ring.
2. On each revolution you get lots of images scanned within 30 seconds to 5 min- this is very fast.
3. The biggest logistical challenge is moving objects to and from the hospital safely.
4. During the scanning you immediately get slices, which are cross-section images from three different directions. Volumetric rendering is done from the slices and there is free software for this.
5. Apparently it is relatively easy to do segmentation, segment out regions of interest, and extract wire frame models, just time consuming. From there you can get images of the surface and texture and can even print the models. It is relatively easy to go from slice to wireframe, but harder to achieve a manufacturing mesh to produce a 3D print, which can be expensive in comparison to traditional molding and casting.
6. PROs of scanning and printing: there is no contact with the object, complex geometry is not a problem, the scans and volumetric rendering are dimensionally accurate, you can print in lots of materials; prints can be scaled to make large things handleable or small things more robust for handling or increase visibility; subtractive manufacture, in which you can use a computerized milling machine to cut out a positive or negative, is also a possibility.
7. CONs of scanning and printing: printing is slow, the build volume is limited, a non-traditional skill set is required of conservators to produce the final product, and only a few materials age well. The best material is sintered nylon, extruded polyester may also be safe, but it doesn’t take paint well; it is hard to get the industry to think about permanence.
The object at the center of this project was a Magdalenian skull. The skeleton itself is of considerable importance, because it is the only magdalenian era skeleton of almost completion. A little history: it was excavated, quite professionally, in 1911 when they lowered the floor of the site. Unfortunately the burial was discovered when someone hit the skull with a pickax. Needless to say, the skull did not come out in one piece. In 1915 the full skeleton was removed in two blocks. My notes are a little fuzzy here, but basically at some point between the excavation the skull was restored and then went from being 2 pieces to 6 pieces, as it is documented in a 1932 publication by von Bonen. It appears that at that point the skull was also skin coated with plaster. Thankfully (?) those repairs have held up. Great, so why, did they need to scan and reconstruct the skull? Well according to Dr. Robert Martin, JP’s colleague at the Field Museum, the skull doesn’t look anatomically correct. Apparently during the time period when it was put together there was an interest in race and the skull fragments could have been lined up incorrectly accentuating cultural assumptions.

A previous x-ray showed that two fragments in the forehead are secured with a metal pin. In 2012, when the mobile CT scanner came to the museum, they were all geared up to start with the Magdalenian skull. Unfortunately there was not much difference in attenuation between bone and plaster making it tricky to define between the two materials in the scans. JP consulted a cranial reconstruction group and asked them to pretend this was a pediatric car crash victim with a cranial injury; they asked, why aren’t you using the mimics software package?

In this scanner, the object sits on a rotating table, while the source and detector stay still. Since these are fixed, a full scan has to be done in parts depending on the size of the object. — In this scanner, the object sits on a rotating table, while the source and detector stay still. Since these are fixed, a full scan has to be done in parts depending on the size of the objec

JP and his team also imaged the skull with a micro CT scan that has a 0.1 mm resolution versus the normal modern setting of 0.3 mm. They had previously identified 36 fragments of bone from the previous scan. It was hard to tell if some of those separations were just cracks or actual breaks between fragments. The hope was that the micro CT scanner could better define these areas. The micro CT scanner works opposite to the industrial/medical scanner. As you can see in the image to the left, the tube and detector are fixed, while the sample is rotated. Other differences are that it is slower, one scan takes 30-90 minutes and because of scanner geometry the skull had to be imaged in two scans . Because of this, JP used the previous scan to mill out a contoured support to hold the skull in the exact position. JP noted that digitally filling in the holes of the skull to create the support was the most time consuming part of that process and suggests using different radio-opaque marker dots to identify left and right for orientation during the later stitching process. With the new scans at least three separations were identified as cracks vs. breaks.
Now for the virtual reconstruction… the biggest obstacle in this stage was how to achieve something more anatomically correct using the virtual fragments when they have no boundaries. The fragments don’t push back in the computer- and the fragments can easily move into each other. With the software JP used mostly the translation and rotation functions and the free animation software Blender (which has a high learning curve and took several days to get accustomed to) to create hierarchical parent child relationships between the fragments as he joined them together. Just like putting a vessel together, right? In the virtual world at least there is no worry about lockout. They had a 3D printed of the final skull reconstruction and had an artist do facial reconstruction, which JP thinks always look related to Jean Luc Picard… So how successful was this? From a conservation perspective- awesome, it’s fully reversible! Scientifically though, it’s decent, well documented and scientifically justifiable- However, someone else could go through the same process and come up with a different reconstruction because of their reliance on left right symmetry for this reconstruction…

Comparison of the current restoration and the virtual restoration — Comparison of the current restoration (left) and the virtual restoration (right)

So what did I take away from this talk? This was a very cool project and if I have a question about CT scanning and 3D renderings, I will call JP! The scans can be extremely informational and there seems to be a lot of potential in their use for mount-making, crates, and storage, and possibly virtual reconstructions. Hopefully at some point in the future the software will become more intuitive and easier to use so that more of these types of projects can be done.

42nd Annual Meeting, Paintings & Wooden Artifacts Joint Session, May 31, "The Analysis and Reduction of an Intractable Coating for the Panel Painting by Lluis Borrassa, Christ Before Pilate," by William P. Brown & Dr. Adele De Cruz

The presentation by William P. Brown and Dr. Adele De Cruz was an awe inspiring glimpse at the future of conservation. Through the collaboration of the North Carolina Museum of Art and conservation scientists from the University of Pisa and Duke University, an intractable layer of cross-linked drying oil, animal glues, and pigmented varnish was removed from the surface of Spanish painter Lluis Borrassa’s panel painting, Christ Before Pilate, 1420-25.
The painting, which had not been exhibited for over 40 years, was the victim of previous cleaning and coating campaigns, and several layers of consolidation materials and paints and glazes had been applied to the blue passages of Christ’s robe. As a result of the cross-linking of these consolidants and the dark pigmentation of a conealing varnish layer, Christs’s robe appeared almost black.
During treatment at the North Carolina Museum of Art, solvents were successful in removing the toned varnish from the painting. However, the reduction of the complex layer of intractable material covering Christ’s robe (the abstract describes this as a composite of old consolidant, cross-linked drying oil, and restoration materials) was not so straighforward. Conservation scientists (from the aforementioned institutions) used FTIR, SEM, and GC-MS analysis to identify the components of the intractable layer and to discern them from original material, which consistsed of lapis, indigo, and orpiment pigments in egg tempera and glue or bee pollen.
Dr. De Cruz took the podium at this point in the talk to describe the methods used to reduce the intractable composite material. Essentially, laser ablation was employed, which before this talk I was only familiar with in the context of dentistry. I have to admit that my intitial reaction to hearing the terms ‘laser’ and ‘art conservation’ used together might have been a wary one, but a refamiliarzing with the techniques involved with laser ablation (and recalling the established use of this technique on the delicate enamel surfaces of our teeth) was an encouraging and exciting reminder of the vast potential of interdisiplanary approaches to art conservation.
Dr. De Cruz explained that the 2940 nm Er:YAG (erbium) operates using an intense monochromatic wave of light (2.94 microwatts) at 15 pulses per second to vaporize the intractable material. The depth of penetration is very controllable, maintaining a shallow depth of penetration between 3-5 microns. This light pulse is highly absorbed by water, and produced a near instantaneous steam distillation. A glass cover slip is placed over the dirt, varnish, and paint layer. The laser is used to break up the intractable surface, which is ejected and contained by the glass cover slip. The debris is then swabbed from the surface of the painting and can be used for analysis.
There are several immediately obvious benefits to this method. It eliminates the need for toxic solvents, it allows for a highly controllable and low shallow depth of penetration. There is also no risk of chemical change to the substrate, and the reaction is low temperature.
Dr. De Cruz went in to incredible depth during this talk, and I realize that my summary only touches on the ammount of information she provided. I was furiously scribbling notes the entire time, and certainly wished I had a camera to take photos of her slides. I certainly look forward to hearing more about this topic in the future, and am excited for the future and ongoing collaboration of conservation and science.

42nd Annual Meeting: BPG Tips Session, May 30, moderated by Emily Rainwater

There were sixteen tips presented by twelve speakers in this session, with a very lively question and comment period at the end.

Tip 1: ‘Beading: A Japanese technique used to relax laminated paper’ presented by Betsy Palmer Eldridge.

When two sheets of paper have been pasted together overall, the result is a sheet that is much thicker and stiffer than the two individuals. Ms. Eldridge described her technique of using a string of beads known as ura-suri to soften, relax, and remove cockling from the laminated paper. She forms the beads into a coil, then makes a repeated circular motion with a flat hand. During the Q&A, Rachel Freeman mentioned that marbles or a Japanese printmaking baren work well too.

Tip 2: ‘Quick and Easy Plexi Paste’ presented by Cher Schneider.

Ms. Schneider developed this method for adhering two pieces of Plexiglas together to make mounts. Step 1: Collect Plexi shavings into a glass container. Step 2: Dissolve first in drops of acetone until it gets milky white, then add drops of toluene until it becomes transparent. Do not stir too much. Step 3: Apply to one side of the joint with a glass stir rod, then attach the other piece. Clear excess with a piece of matboard, then with a swab dampened with toluene. Step 4: Cure for 15-20 hours. Step 5: Clean glass tools by popping the dried Plexi paste right off. She does not recommend trying to re-use dried Plexi paste. During the Q&A, John Baty suggested a bake-out to cure the paste.

Tip 3: ‘Alt Training’ by Beth Doyle.

After struggling with the difficulties of providing care and handling training to temporary and permanent staff and students, Beth Doyle of Duke University Libraries figured out that using social media to make short training videos on specific topics is a great way to reach everyone in a timely manner. The instagram videos are 15 seconds and the youtube videos, such as this one, are 2 minutes. If you want to make your own, she recommends using multiple paths to reach the largest audience, exploiting what each platform has to offer, reusing and recycling clips where possible, accepting that what you have is good enough, and keeping it short.

Tip 4: ‘Studio-Lab Weight Sources’ by Stephanie Watkins.

Ms. Watkins reviewed the types of weights that conservators use, with suggestions for how to find or make your own. Because they are by nature heavy, she suggests above all that looking locally or making your own is the most cost-effective, and in the spirit of the meeting, ecologically sound. If you do have to have some weights shipped, she recommends USPS flat weight priority. Items that have been used as weights include magnets, sewing weights, scuba, exercise and fishing weights, car tire balancing weights, glass scraps, paperweights, flat irons, shoe anvils, weights manufactured by conservation suppliers, hand-crafted weights, scrap metal, and heavy items from freecycle. Home-made weight fillings include ball bearings, BB shot, coins, stones, sand, glass, beads and beans. Modifications can include polishing, covering, and adding smooth boards, felts, handles, and fabric. Form follows function, so determine the size and shape needed, then look around to see what is available.
I commented on this tip to add that a friend who sometimes has to travel out of the lab to do conservation work on-site brings empty containers and fills them with water for make-shift weights.

Tip 5: ‘Cling and Release: Silicone Mylar+Japanese Paper+Wheat Starch Paste= A One-Step Hinge for Float Framing’ by Terry Marsh, read by Anisha Gupta.

This PDF ( TerryMarsh-OneStepHinge ) explains the process.

Tip 6: ‘Aquazol as a heat-set adhesive’ by Adam Novak.

Mr. Novak presented two quick tips. First, he shared his recipe for heat-set tissue, based on research by Katherine Lechuga, summarized here. He makes a 6% solution of Aquazol 500 in deionized water and brushes it on very thin (2 gram) tengujo paper. After cutting the repair strip, it can be set in place temporarily using the heat of his finger. Then, he places silicone release paper over the repair and sets it with a tacking iron. (When questioned later by Sarah Reidell, he indicated that he did not know the exact temperature used with the tacking iron, but supposed that it is in the range of 150 degrees F.) The repair may look shiny in comparison with surrounding paper. If this is the case, shine can be reduced by brushing on a bit of ethanol.

Tip 7: ‘Using pH strips with filtered water’ by Adam Novak.

The second tip addressed the issue of very different readings with a pH strip and a pH meter when measuring deionized water solutions buffered with calcium hydroxide. This is something that I had noticed in my lab at NYPL, and was glad to hear an explanation. Mr. Novak has discovered that the conductivity is very low in the calcium solutions and that there is not enough ionization to get an accurate reading with the strips. This is only the case with calcium- other buffers have higher conductivity and the strips read more accurately.

Tip 8: ‘Cellulose Powder’ by Becca Pollak.

(photo of slide taken by Valerie Faivre)

Ms. Pollack described her technique of spraying cellulose powder with an airbrush to minimize local discoloration on paper, cover foxing, or prepare for inpainting. She sprays the powder directly through stencils and adds pigments for toning if necessary. The basic recipe is below as a starting point, but adjustments may need to be made depending on its moisture sensitivity of an object or the desired effect. She also sprays films on Mylar and allows them to dry for future use. In that case, she sprays a layer of plain methylcellulose first to improve cohesion of the sheet. Ms. Pollak is preparing a tip sheet to be posted soon.

Basic recipe:

Approximately 20mL 0.5-1% Methocel A4M (Ms. Pollack reports that Elissa O’Loughlin prefers 1-2% of A15C; and Jim Bernstein prefers a mixture of cellulose ethers or gelatin.)
5-10mL isopropanol
1g of micro-cellulose powder

Tip 9: ‘Applying New Techniques On A Traditional Adhesive For Book Conservation’ by Marjan Anvari.

Traditional, western conservation training in book and paper conservation centers around the use of wheat starch paste. Ms. Anvari is an Iranian conservator working on middle eastern objects and decided to develop a repair adhesive based on a traditional Iranian adhesive that is also flexible and reversible in water. This adhesive, used by artists and artisans and known as ‘green paste,’ is dark yellow in color and leaves a stain, so Ms. Anvari worked to purify it, and came up with an acceptable recipe. She gave out samples at the end of the session. The paste can also be acquired from Raastak Enterprises, which can be contacted for more information.

Tip 10: ‘Flattening translucent paper’ by Laura Neufeld.

Ms. Neufeld tested four techniques for flattening thin papers: Mylar flattening, the hard-soft sandwich technique, friction flattening, and edge flattening. A gampi-fibered paper was used for testing. The Mylar flattening technique, featured in the article ‘The conservation of three Whistler prints on Japanese paper’ by Catherine Nicholson, required the paper to be fully wet and gave the paper a slight sheen. The hard-soft sandwich technique, featured in the article ‘Architectural Drawings on Transparent Paper’ by Hildegard Homburger, did not require much moisture and removed severe creases. The sandwich calls for polypropylene fleece., but Ms. Neufeld found that this can be substituted with polyethylene fleece or Gore-Tex with the fuzzy side away from the object. Friction flattening, described in the article ‘The Use of Friction Mounting as an Aid to Pressing Works on Paper‘ by Keiko Keyes, can have similar results as using a kari-bari and has been found to work well on both old master and Japanese prints. She found edge flattening to be the most difficult. This slide (Flattening_Slide) shows the results in normal and raking illumination.

Tip 11: ‘Tek-wipes’ by Gwenanne Edwards.

Tek-wipes, which are used in the computer and custodial industries, were mentioned on the DistList and handed out at last year’s Tip Session, and it seems that the word is out; many people have been discovering uses for them in paper conservation. Ms. Edwards likes to use them for capillary washing, slant washing, suction washing, as a support for lining, for drying and flattening, and in emergency response. She recommends them because they are highly absorbent, strong, reusable, machine-washable, dimensionably-stable, you can vary their saturation, they pull discoloration out well, they are safe with solvents, and they are way cheaper than blotter. They are available from a number of sources under various trade names, such as Texwipe or Technicloth. The overwhelming majority of commenters at the end of the session wanted to talk about Tek-wipes and other blotter replacements. Seth Irwin uses them to pull tidelines from paper using a tacking iron. Betsy Palmer Eldridge suggested that they would work in some of the drying techniques tested by Laura Neufeld (above.) In Australia, they use bamboo felt and interfacing in place of blotters. Bill Minter said that Christine Smith uses bath towels. Anna Friedman uses Sham-wow(warning: this link takes you to the company page with a video commercial).

Tip 12: ‘Rare earth magnets to make solvent chambers’ by Anne Marigza.

(photo of slide taken by Valerie Faivre)

Ms. Marigza uses rare earth magnets in a solvent chamber. One on either side of the inverted glass or Mylar container will hold the solvent-saturated blotter (or other absorbent material) in place. The magnet can be discarded when it becomes powdery.

Tip 13. ‘Flattening Rolled Drawings for Digitization’ by Bill Minter.

(photo of slide taken by Valerie Faivre)

Mr. Minter developed a method for flattening architectural drawings by reverse-rolling. He places a cardboard tube at the edge of the table with an attached paper extension hanging down to the floor. He places the leading edge of the drawing in the roller, then rolls it the opposite way and lets it sit for a day. When unrolled, it lays flat enough for digitization.

Tip 14: ‘Velcro for Phase-Boxes’ by Bill Minter.

Do you find your velcro hooks and loops to be too strongly attached to each other that they do not pull apart easily? Mr. Minter has discovered a less aggressive velcro. Instead of being labelled as such, the only way to distinguish is that the box is marked ‘clear.’ It comes in strips, discs, or rectangles.

Tip 15: ‘Dry-Tearing of Paper for Infills’ by Bill Minter.

(photo of samples taken by Valerie Faivre)

Lay some wire mesh on a flat surface and place the infill paper on top. Run the tip of an awl, needle, or other pointed instrument along the line you want to tear. It will create a perforation that can be dry-torn. McMaster-Carr sells wire mesh different gauges and materials. Above are samples of two sizes.

Tip 16: ‘Toning of Paper’ by Bill Minter.

The Preval sprayer works great for small paper-toning projects. Clean well after use. During the Q&A, we learned: They sell replacement valves if the ones you have get clogged. The glass jars can be saved and reused.

42nd Annual Meeting – Architecture + Objects Joint Session, 29 May, 2014, “Conservation Realities and Challenges: from Auto Regulation to Imposition at Archaeological and Historical Sites in Colombia” by Maria Paula Alvarez

I was drawn to this presentation on account of my background in archaeology. Although I have never had the chance to visit Colombia, I was very interested to hear about the challenges, that Colombian conservators, archaeologists, and other allied professionals encounter in their efforts to preserve their country’s archaeological and historical sites.
Maria Paula Alvarez, Director at the Corporacion Proyecto Patrimonio, presented a number of interesting case studies to illustrate the types of conservation and preservation problems that she and her colleagues face and work on solving. Her examples included assessments, research, testing, and treatments at
1) archaeological sites, such as:

The Archaeological Site of Fuente de Lavapatas, where the conservation issue was stone deterioration. Extensive studies – including the evaluation of the environmental conditions at the site and the geological and physical properties of the affected stone – were conducted to determine the causes of deterioration. As well, testing of treatment materials – including biocides for controlling biodeterioration and consolidants for disintegrated areas – were undertaken.

The Archaeological Park of Facatativa, where panels of rock art were deteriorating not only as a result of exposure to the natural environment, but also as a result of exposure to humans. Both biodeterioration and vandalism in the form of graffiti were damaging to the rock art panels. The panels received conservation attention for both problems.

2) and historical monuments, such as:

The Jimenez de Quesada Monument in the city of Bogota, which had been damaged as a result of vandalism in the form of graffiti. The monument received a conservation treatment that included both the removal of the graffiti as well as the application of a coating to protect the monument against future graffiti vandalism.

In all of the cases that she presented, Maria spoke about the effect of the political, social, and economical climate on the sites’ conservation and preservation. She stressed the impact that such climates have on cultural heritage, from the care to the destruction of sites. She explained how various political, social, and economical circumstances have led her and her colleagues to determine goals and procedures for conservation and preservation projects. I found these concepts very powerful. For me, this presentation was a strong reminder of the complexities involved in the preservation of cultural heritage.

42nd Annual Meeting- Textile Group Session, May 30, 2014 "Blown-Up: Collaborative conservation and sustainable treatment for an inflatable dress" by Chandra Obie

Chandra Obie, textile conservator at the Cincinnati Art Museum, presented her work on the conservation of an Issey Miyake pneumatic dress with inflatable puffy sleeve caps. The circa 2000 dress had lost its ability to remain inflated with the failure/deterioration of adhesion on the rubber valve sleeve stoppers. The dress was donated to the museum by Mary Baskett, a collector of Japanese contemporary fashion, who’s costume has been displayed in the 2007 Cincinnati exhibition Where would you wear that? and 2009 at The Textile Museum in DC. This particular dress presented the unique challenge that Mary had full intention on wearing the dress out in public to special events after treatment. Therefore, the treatment methodology combined the collaboration of appeasing a major donor while conserving the original shape of the sleeve.
The dress came with a 4-page care/construction tag displaying that the dress was 42%Nylon, 40%Polyester, and 18%Polyurethane. The photo oxidation of the urethane caused yellowing and deterioration of adhesion around the valves which prevented the sleeves from remaining inflated. Chandra further consulted with scientists and conservators via the Conservation distlist before beginning treatment. Step one involved testing different methods for recreating the inflated sleeve shape. Initial solutions of creating a cage structure inside the sleeve or using a medical plastic balloon failed due to access and stability of materials. The re-adhesion of the vinyl inflation valves was attempted with craft glue, silicone, and BEVA, which all failed adhesion. Step two developed the creation of a sleeve pattern using Stabiltex, a semi-transparent light weight polyester fabric, filled with polystyrene beads and a polyethafoam cap. The Stabiltex edges were finished using a heated spatula to weld the polyester and prevent fraying, and a double layer was used for strength. The sleeve was inserted into the cap and carefully placed along the original pattern, while a funnel was used to fill the cap with polystyrene beads. The inflatable valves were tacked back into place with a few stitches. After treatment, Mary Baskett wore her Miyake dress out for her birthday party, and was very pleased with the return of the inflatable sleeve shape. The only noticeable difference while wearing the garment was the tendency for the sleeves to shift forward on her body.
While the treatment was successful, post-talk discussions with other conservators presented the apprehension of long-term stability of the polystyrene beads.

42nd Annual Meeting- Electronic Media Session, May 31, 2014, "The California Audiovisual Preservation Project: A Statewide Collaborative Model to Preserve the State’s Documentary Heritage by Pamela Jean Vadakan"

The California Light and Sound Collection is the product of a collaboration between 75 partner institutions with original recordings of audiovisual content in California. Following a 2007 statewide collection survey that used the University of California’s CALIPR sampling tool, it was discovered that over 1 million recordings were in need of preservation. In 2010, the California Audiovisual Preservation Project (CAVPP) was founded. Recipients of a National Leadership Grant from the Institute of Museum and Library Services (IMLS), the CAVPP uploaded its first video in 2011.
Like previous statewide initiatives within the California Preservation Program, the project is based at the University of California at Berkeley, where Barclay Ogden provides leadership for the project. By repurposing existing staff and existing tools, the project is able to realize a high level of efficiency. Each partner institution is responsible for surveying its own collection with CALIPR, adding its own records to CONTENTdm, and sending its own recordings with metadata to CAVPP. It is anticipated that open-source tool OMEKA will replace CONTENTdm, because the project partners should not be dependent upon costly proprietary software site licenses.
CAVPP adds administrative metadata, confirms the descriptive metadata, and sends content to the vendors. The vendors include MediaPreserve, Scenesavers, and Bay Area Video Coalition. The vendors produce a preservation file, a mezzanine file, and an access file for each item. Moving forward the project will discontinue creating the mezzanine file, because the preservation file is more useful. Two copies of each file are saved to Linear-tape-open (LTO) and one on the Internet Archive’s servers. Storage costs are about five dollars per recording. CAVPP is also responsible for running checksums and checking video quality. Problems have included out of sync audio, shifts in hue or saturation (chrominance), and shifts in value (luminance). The AV Artifact Atlas has proven essential to the quality control process.
It is crucial for a project this large to have a clear scope in terms of both content and format. The criteria for selection include statewide or local significance, unpublished or original source material, and public domain content. The project also encompasses content for which rights have already been acquired. In some cases, “unknown” has been used a placeholder for missing copyright information. The materials are also subject to triage in terms of the original physical format and condition (preservation need). The project is limited to digital conversion. Film-to-film conversion is outside the scope of the project, but it is hoped that project partners can leverage this project to facilitate projects for high-definition video and film-to-film conversion.
The project has already exceeded its original goals. In the first year, CAVPP uploaded 50 recordings. Now the project has grown to 75 institutions and over 1,400 recordings. It is anticipated that there will be over 3,000 recordings by the end of 2014. Future steps include an assessment of who is using the collection and how they are using it. The project also includes outreach workshops scheduled for project partners in 2014 and 2015.

42nd Annual Meeting- Book and Paper Session, May 29, 2014, "The impact of digitization on conservation activities at the Wellcome Library by Gillian Boal"

The Wellcome Library relies on cross-training and written policies to facilitate the increased involvement of non-conservators in the digitization workflow. Gillian Boal explained that the Wellcome Library, the UK’s largest medical library at over 4 million volumes and the public face of one of the world’s largest private charities, aims to digitize its entire holdings. In order to provide free online access to the entire collection, they have to involve a large group of internal and external partners. Some items are scanned in-house, while others are contracted out to the Internet Archive.
The role of the conservators is primarily to ensure safe handling of the original physical items. To that end, they have trained allied professionals to serve as digital preparators, empowered to perform minor conservation procedures. Treatments are divided into two groups: dry and wet. Dry treatment includes removal of paperclips and staples, for example. These dry procedures are often performed outside of a conservation lab by archivists and librarians in many institutional contexts where there are no conservators. Those procedures are an obvious fit for the non-conservators working on the project. Wet procedures include both aqueous and solvent treatments. Wet treatments are more likely to require the skills of conservation personnel with lab equipment.
Complex folded items presented a special challenge that was met with creativity. The presentation included examples where overlapping parts were lifted onto a cushion of Plastazote™ cross-linked polyethylene foam during digitization. Boal pointed out the shadows visible in the scanned documents where overlapping parts were supported by these foam shims. This is important because the customary use of a glass plate to hold materials flat for photography would have added extra stress or new creases in the absence of a cushion. The digital preparators were empowered to use their own judgement to open non-brittle folded items without humidification; such items were held flat under glass for scanning. Other items were photographed without glass, to accommodate three-dimensional paper structures.
The Internet Archive also acted as a preservation partner, re-routing items to conservation as needed. For example, a volume with a torn page was intercepted by the Internet Archive’s assessment process in order to receive treatment by the conservators.
The digitization of collections is primarily about access. To enhance that access, the Wellcome Library developed “the player” as a tool to view a variety of different types of content from the same interface. It enables downloading or embedding a zoomed-in part of a page, in addition to options for high-resolution and low-resolution images. “The player” also functions as a sort of e-reader interface for books, and it responds dynamically to create the appropriate interface for the type of item accessed, including audiovisual files. It supports both bookmarking and embedding content into other webpages. The Wellcome library is offering the digital asset player as an open-source tool through GitHub.
Boal emphasized the role of policies and documentation in ensuring good communication and trust between partners in such a large project. She also showed examples of handling videos that were created for the project. She would like to see the use of videos expanded to help to create a common vocabulary between conservators, allied professionals, and other stakeholders. The responsibility for collection care is not the exclusive territory of the Collection Care Department, so the key to the ongoing digitization process at the Wellcome Library is the distribution of that responsibility to all of the staff (and external contractors) involved in the project, guided by training, planning, and policies.