The inaugural meeting for this group took place on May 31, 2013 at the AIC Annual Meeting in Indianapolis, ID. Organized by Nancy Ash, Scott Homolka, Stephanie Lussier and Eliza Spaulding, the session presented the Draft Guidelines for Descriptive Terminology for Works of Art on Paper which is a project under way at the Philadelphia Museum of Art and supported by an IMLS 21st Century Museum Professionals Grant.
Continue reading “AIC's 41st Annual Meeting- Art on Paper Discussion Group”
Category: Specialties
41st Annual Meeting – Objects Session, May 30 – Three Decades Later: A Status Report on the Silver Lacquering Program at Winterthur by Bruno Pouliot, Catherine Matsen, Jennifer Mass, William Donnelly, Kaitlin Andrews, & Margaret Bearden
For me, this presentation was one of the high points of the conference – a thoughtful re-examination of a typically undertaken protocol.
The Winterthur Museum collection of silver numbers around 11,600 and over 2,000 of those pieces are on display in period rooms and galleries at the museum. Indeed, as characterized by Bruno Poliot, this is a massive task. To reduce wear and handling, silversmith and then conservator Don Heller began a program of cleaning then coating silver in 1974. After a period of experimentation, Don chose to use Agateen Air Dry Lacquer #27, a cellulose nitrate, for coating, suggesting that it should be replaced every 10 years but could last up to 28 years in a museum environment with careful handling. Over 1000 silver objects were thus treated between 1982-1987. While the conservators at Winterthur experimented other coating materials, including Acryloid B-72 and Acryloid B-48N in the decade that followed, research undertaken by conservation scientist Chandra Reedy and others, presented in the OSG Specialty Group at the 1999 AIC annual meeting, indicated that cellulose nitrate prevented tarnish better than acrylic resins, and Agateen #27 became the only lacquer used for silver at Winterthur from 1997 onward.
In 2009, the collection on display was surveyed systematically to assess the condition of the lacquer coatings. They found that:
- the lacquer on 42% of the objects had moderate to major problems and would require cleaning and re-lacquering
- condition of the coating did not directly correlate with age, method of application, or composition of the silver alloy
- condition of the coating did correlation with how well the lacquer was applied and the complexity of the object’s surface
- the degree to which the coating had yellowed was difficult to assess, but it was found along with tarnish
In 2011, the museum received a 2 year grant from IMLS for a re-lacquering project. The objects to be treated were grouped into one of three categories:
- objects treated in 1985 or earlier,
- those with coatings which were defective or otherwise failing,
- objects which had never been lacquered before. These were often complex.
Procedures for re-treatment were standardized in order to reduce the amount of application defects. Two conservation assistants were hired for the project, and they underwent a two month training program, working on simpler objects before moving on to more complex ones. Bruno did go into a fair amount of detail about the treatment procedures, and I’m sure his paper will also explore those in greater depth than I will here. One key feature of their procedure is examination one hour and then again 24 hours after application of the lacquer to look for imperfections and iridescence, which would indicate that the coating is too thin. Then a final examination of groups of objects is undertaken 2-3 weeks after the lacquer has been applied to ensure that all solvent has evaporated out of the film and to ensure that the coating is free of defects. Touch-ups to the coating can then still be done, and this period allows enough time for the solvent to completely evaporate, ensuring that it is safe to return them to display.
The team also investigated how Agateen #27 ages, looking both at objects coated with the lacquer in Winterthur’s collection as well as from the collections of two individuals who kept their pieces in home environments. The coatings on the pieces from the private collections exhibited a particular pinkish-brown discoloration, not found on any of the museum pieces. Though analysis of degraded coatings with FTIR and XRF and SEM-EDS provided information about the breakdown of the nitrocellulose polymer and elements found within the degraded films, it was the results of Time of Flight-Secondary Ion Mass Spectroscopy (TOF-SIMS), used to further characterize corrosion within degraded nitrocellulose films, that provided some unexpected results.
In TOF-SIMS, a high energy primary ion beam bombards a sample to ionize molecules on the sample surface. These ionized molecules are then characterized using mass spectroscopy. Looking at the lacquer films from the silver from the private collections, silver sulfide, silver oxides, silver chloride, silver sulfate, sulfate anion and silver cyanide were identified. Except for silver cyanide, all of these corrosion products were also identified in tarnish and corrosion products on uncoated silver.
Bruno pointed out that silver cyanide ranges in appearance from colorless to grey-white in color but could result in the pink-brown color noted in the lacquered objects if mixed with cuprite, which is another corrosion product found on silver objects due to a low copper content. They will next determine whether silver cyanide remains on the silver once the degraded lacquer has been removed and whether this corrosion product is detrimental to the silver.
This pink-brown discoloration was the topic of discussion following the talk. One conservator noted that she had also encountered this condition on lacquered silver from a private collection, and that the condition re-occurred within a few months following re-treatment. She mentioned that Agate, the company which produces Agateen, suggested that this might be a result of exposure to direct sunlight. Another conservator suggested that one potential source of cyanide might be a dip that was used in the past to plate or clean the silver, and that these dips may form complexes on the silver surface which may affect or react with a lacquer treatment. We need to look at how a past procedure may affect a current treatment.
Bruno concluded his presentations with a list of recommendations based on the 550 silver objects completed, and as the team at Winterthur contemplates re-lacquering 500 more pieces in 2015.
- The condition of nitrocellulose coatings on complex silver objects should be re-assessed every 5-10 years, given their finding that the majority of the coatings on complex silver objects failed within a 10-15 year time frame.
- When considering application of cellulose nitrate lacquers on silver, resources and time to maintain a silver lacquering program need to be considered as the time needed to remove and replace a cellulose nitrate lacquer is significant.
- Research into how degraded nitrocellulose lacquer affects silver needs to continue, as does finding alternative options for protecting silver against tarnish.
41st Annual Meeting – Electronic Media Session – June 1st – “The Role of the Technical Narrative for Preserving New Media Art” by Mark Hellar
Mark Hellar used the example of the website artwork “Agent Ruby“, acquired by SFMoMA in 2008, and how the use of a technical narrative has helped with the continued preservation of this evolving work of art.
The “Agent Ruby” work was interactive, so it required many components that worked together. The technical narrative had 4 parts:
1. A high level functional description of the artwork
2. Modular examination of components and how they work as a system
3. Detailed description of the artwork as it exists on acquisition, and how the components serve the operation.
4. Analysis of current technology and longevity
“Agent Ruby” is an avatar made up of 22,000 entries that create Ruby’s personality. Visitors interact with Ruby online in a chat setting. The archive of the work from 2001-2009 of visitor interactions was an 80 GB text file. There were some non-essential components that were archived like the original interface and a 3-D model and Hellar discussed how these types of artworks have many components and how the obsolescence of one component (like Flash which is now unsupported on an iPhone) will require creative solutions to allow the work to continue to function.
A migration plan was discussed with the artist, and it was interesting to note that the artist did not want the AIML Interpreter to be updated, even though when Ruby is asked “Who is the President of the United States” she answers “George Bush” the artist said about this, “Ruby will learn”.
41st Annual Meeting – Electronic Media Session – June 1st – "A hands-off approach to controlling media-based artworks" by Brad Dilger and Richard McCoy
Brad Dilger showed how the IMA has transitioned from manually controlling all media-based artworks (meaning that someone had to physically turn on every artwork at the power source each day) to the current system that can be controlled remotely. He walked us through the process of choosing different systems, the museum began using a server which crashed when devices were added or taken away and a programmer had to redo the whole system each time which was expensive. The second version of the system was a stable integrated control system, they had 3 manufacturers to choose between: Cresteron, Exteron, and AMX. Exteron was the only system that had an open source, free configuration and wouldn’t require a certified technician for maintenance. The Exteron processor was made to function as a network or a stand alone device with serial communication and/or a remote power control unit (RPC) power strip.
The Exteron setup has a software configuration is straightforward to use, and the user can set up a schedule, and set notifications by e-mail, for example, for projectors it is possible to set up an e-mail notification when the lamp bulb nears 2,000 hours so the bulb can be changed. The system prevents circuits from overloading if the artwork requires a high draw (13 amps).
He showed 2 case studies: Julianne Swartz’s 2008 “Terrain” and Will Lamson’s 2010 “A line describing the sun” and how those two works functioned using the Exteron system. The presentation offered many solutions to the issues surrounding the display and maintenance of electronic artworks.
TIMBUKTU NEEDS YOU NOW!
Last week, PMG members were challenged to participate in the rescue effort called T-160K Timbuktu Libraries in Exile and help raise fund to protect 300,000 precious manuscripts that were evacuated last year from Timbuktu in the midst of a civil war.
Our goal was to help raise $1500 for the preservation of 50 manuscripts; it was met a few days ago. To this day PMG members have contributed enough funds to preserve more than 60 manuscripts.
I am now challenging you, Facebook Friends of AIC, to join the fundraising effort. If each of you contributes just $1 to the campaign, you could help preserve 231 additional manuscripts!
Hurry up, there are only a few hours left to contribute and join this great learning adventure of the Timbuktu Libraries. To show your support, make your donation directly at http://www.indiegogo.com/projects/timbuktu-libraries-in-exile/x/3254149?c=home and “like” this posting.
How your contribution makes a difference:
All of the funding raised through the Indiegogo campaign will serve a single purpose: better accommodate the manuscripts (individual boxing, buffering and humidity control while maintaining mobility so that the manuscripts can be moved in the case of an escalation of socio-political strife in Mali) to lessen the risk of deformation and arrest microbial infestation that are imminent and will lead to very significant loss of substance.
Many thanks,
Sylvie Pénichon
Chair, Photographic Materials Group
American Institute for Conservation
41st Annual Meeting – Book and Paper Session, June 1, "Conservation and Encasement: 1297 Magna Carta" by Morgan Zinsmeister and Terry Boone
In 2011, senior conservators Morgan Zinsmeister and Terry Boone of the National Archives and Records Administration (NARA), thoroughly documented, conserved, and encased a copy of Magna Carta that dates to 1297. During his presentation at AIC’s 41st Annual Meeting in Indianapolis, Zinsmeister recounted the project. His presentation, which I’ve summarized in this post, beautifully illustrated the measures taken by NARA conservators to preserve documents and artifacts so essential to the history of our nation.
First drafted by a gang of rebellious barons in 1215, Magna Carta asserted the individual and property rights of its authors in opposition to the tyranny of King John of England (1166-1216). This document also addressed the fundamental principles of majority rule and due process that would prove essential to later charters. Magna Carta served as a precedent to the British Constitution, the Bill of Rights, Declaration of Independence, and U.S. Constitution.
Magna Carta, 1297 after treatment
Between 1216 and 1297, Magna Carta was reissued four times and copied many more. Today, 17 extant copies are known: 15 in the United Kingdom, one in Australia, and one in the United States, that is the copy conserved and exhibited at NARA courtesy of its current owner, David M. Rubenstein.
Magna Carta, 1297 is written Latin with iron gall ink and metal-point ruling on parchment. A sur double queue wax seal with parchment tag served as a closure. When the document was removed from its previous encasement–an anoxic acrylic case designed by Dr. Nathan Stolow at the Harry Ransom Center at the University of Texas at Austin–it was closely monitored for change as parchment is extremely sensitive to moisture and fluctuations in relative humidity. Once removed, Magna Carta was examined closely and its condition documented. It was during this examination period that conservators made the happy discovery that a portion of the text previously obliterated by water damage was made legible again through photography using ultraviolet radiation. To learn more about this discovery, see a past blog post by AIC’s own E-editor Rachael Perkins Arenstein.
Following thorough examination and documentation, a three-step treatment was devised that included removal of previous mends, reduction of adhesive residues, and humidification and flattening of the document in preparation for re-encasement. Magna Carta was first selectively surface cleaned. Next, adhesive residues were carefully reduced, old repairs removed, and acrylic-toned, handmade kozo (long-fibered mulberry paper) used to create new fills and repair tears. Prior to humidification and flattening, transparent polyester film was used to make outline tracings of Magna Carta to document any dimensional changes that might occur during treatment. Humidification was carried out using the damp-pack method and the document was dried under tension for several months to allow the moisture content of the parchment to reach equilibrium.
The tight environmental control required to preserve Magna Carta lead NARA staff to partner with the National Institute of Standards and Technology (NIST) in designing the new encasement. Together, NARA and NIST developed an anoxic (without oxygen) display that inhibits oxidative degradation to preserve the document as long as possible. A perfect collaboration!
Installation of Magna Carta, 1297 in its new encasement at NARA
To create the new encasement, NARA drew upon past experiences housing important documents and applied lessons learned from encasement of the Charters of Freedom: the Bill of Rights, the Declaration of Independence, and the U.S. Constitution. Magna Carta was scanned and its exact profile obtained to produce a custom support that would eliminate any strain to the document and protect it from damaging vibrations. A special paper with high alpha-cellulose content created by Timothy Barrett was used as a barrier between the document and the encasement’s metal support. Ultimately, this paper serves two functions: it works as a buffer to help maintain the desired relative humidity within the encasement and as a sort of non-invasive optical brightener. The whiteness of the paper barrier combined with the parchment’s translucency actually caused the document appear more luminous! Polyester film tabs with rounded edges hold the document in place. The encasement is fitted with o-rings to create a tight seal and a leak-detection system. Once sealed, the air trapped inside the case was flushed out using the inert, humidified argon gas to create an oxygen-free environment.
In March 2012, Magna Carta, 1297 was re-installed in NARA’s West Rotunda where it remains on view. When we take a moment to reflect upon the important role that historic documents like Magna Carta play in telling the story of a nation, their preservation becomes unquestionable and the essential nature of the conservator’s work is underscored. Thanks to the amazing work of NARA conservators Morgan Zinsmeister and Terry Boone, their collaborators at NIST, and David M. Rubenstein who brought the document to NARA and underwrote its treatment and encasement, the Magna Carta will be preserved for the education and enjoyment of many generations of visitors to come.
To learn more about the exciting story of Magna Carta’s preservation, visit NARA’s website or YouTube channel to view videos on the treatment and the encasement.
41st Annual Meeting – Objects Session May 31, “Bringing History to Life: Reproducing a Worthington Steam Pump from the USS Monitor” by William Hoffman, The Mariners’ Museum
One of the most remarkable things about the field of Conservation is its ability to bring together art and science, cutting edge technology and time-honored skills to preserve original historic or artistic works while gaining new insights into how they were produced and making them more accessible to everyone.
These aims seem very much at the heart of the remarkable project presented by William Hoffman in his paper which described the process of studying the manufacturing techniques of a Worthington steam pump excavated from the shipwreck of the historic ironclad USS Monitor which sank in 1862 and building a full scale working replica.
The two original Worthington steam powered water pumps from the Monitor, the earliest known examples of their type, are in remarkable condition considering the nearly 140 years spent in a marine archaeological context before their recovery in 2001. The pumps are nearly finished conservation and will be placed on display at the Mariners’ Museum USS Monitor Center, but the extensive corrosion of the cast iron and copper alloy parts has left them in a fragile condition. The project began to take shape out of the desire to convey the original movement and function of the object to the public in a way which was far more immediate than a computer simulation could achieve alone. I thought this seemed intriguing, and particularly poignant in a digital age when high quality digital renderings have become omnipresent.
Hoffman explained that by conserving, studying and documenting the evidence of the original materials and the molding, metal casting, fabrication, and machining processes used, an approach to making the replica was formulated, using a combination of traditional technical and art metal casting techniques, and the use of modern 3D scanning, CAD, and 3D FDM (force deposition modelling) printing techniques to aid in the pattern and mold making. No less important is the final machining of the parts, made easier by the use of modern computer driven CNC tooling. The resulting replica is well underway and it’s hoped that the fully working replica will be operational in the near future.
Hoffman’s talk was very engaging and made use of digital drawings, animations, and video footage of the replication process, all of which helped to relate a detailed process in a way which was easy for the audience to follow. The enthusiasm of the author and the team of conservators, museum staff, volunteer researchers, 3D scanning and printing specialists, metal casters, machinists, and industry representatives who had helped to make the project a reality came through clearly, as did the high level of interest in the use of the replica pump for multiple educational programs, highlighting the need for conservation of our shared heritage and the information and experiences it can bring to light.
AIC 41st Annual Meeting – Contemporary Art Sessions, May 31, 2013, “When Conservation Means Stapling: Touring an Unsupported, Unglazed, 9ft x 21ft, Oil Paint Stick on Paper to Three Venues by Joan Weir”
Joan Weir, conservator at the Art Gallery of Ontario, gave an informative Contemporary Art Session talk about the exhibition of Richard Serra’s 9’ by 21’ oil paint stick on paper, Untitled, 1974. She presented information about Serra’s working methods, and discussed challenges that conservators may encounter when working with oversize contemporary works of art on paper. I was particularly interested in learning about the process she used to mount the two horizontal sections of the drawing directly onto the wall with staples, because I had experienced the more modest challenge of how to mount an unglazed, unframed 8’ by 6’ contemporary charcoal drawing on a gallery wall.
Untitled, 1974, predated Serra’s use of the “bricks” he created from the individual oil paint sticks to facilitate the application of his medium. In 1974, he was still using individual oil paint sticks. When Weir unrolled the drawing from the 7’ storage tube, she observed that the oil paint stick medium on the upper sheet of paper was still flexible and in good condition, but had milky areas that appeared to be bloom.
After 30 years of being rolled, the paper remained strong enough to exhibit. The recto of the bottom sheet was disfigured with yellow stains. Since it contained no drawing media, Weir obtained permission from Serra to display the unstained verso side of the bottom sheet instead of the recto.
Untitled, 1974 had been exhibited without glazing or a frame less than four times, and had staple holes along the edges from the prior installations. Weir explored alternative hanging methods and finally embraced the idea of using standard 3/8” staples applied with a manual stapler. Prior to exhibition, she mended preexisting staple holes with Japanese tissue and a dry starch paste as needed. Post exhibit, she removed the staples with a Bosch staple remover, after inserting a protective Mylar strip beneath them.
To establish a safe procedure for the installation process, Weir created mockups of the same size as the drawing and practiced installing them. She determined that a courier team of two people was required to install and de-install the drawing, and used the same team and procedures for each of the three venues. The installation process also required 16’ of clear floor space in front of the wall, two scissors lifts, eight technicians, and shutting down the HVAC openings. A collapsible, portable raised work surface composed of Gator-board on folding tables “went on tour” with the rolled drawing. The stapling process was entrusted to a member of the Serra Studio team.
The installers practiced the installation two or three times at each venue prior to attempting the actual mounting of the drawing. They used tape on the wall to guide the placement of the drawing.
Weir described the installation procedure to AIC meeting attendees while she showed a video clip of the drawing being mounted on the wall. Seeing the actual process was very helpful. I hope she will add the video clip to the electronic version of her article as a valuable resource for anyone with a similar installation project.
During the first exhibit, she said that a sagging pouch formed along the top edge of the paper. By acclimating the drawing in the exhibit space overnight and refining the installation technique, she was able to prevent gaping by the third venue. The staples held very well.
Weir noted that the exhibited drawing accumulated many dust fibers and hairs, which she attributed to the HVAC systems. The requirement for constant supervision by a security guard prevented all but one touch incident, which she found remarkable.
Weir stated that this project had a number of high risks, especially the possibility of permanent damage from improper handling during the installation and de-installation process. Using the same people and procedures reduced the risk. This consistency was supported by all of the museums, the artist, and his studio, and it helped ensure the safety of the drawing.
This cooperative spirit extended to the relationship between the artist and the conservator. Weir respected Serra’s intent for how his work should be viewed. Instead of trying to promote traditional conservation ideals of how paper should be displayed, she worked to find the safest way to display his art without glazing or a frame.
Stapling art to the wall isn’t the first thought that comes to my mind when thinking about optimal exhibition methods. Contemporary art often requires unconventional approaches. Weir developed a workable solution that protected the drawing while allowing viewers to experience Untitled, 1974 as the artist intended.
41st Annual Meeting, Textile and Wooden Artifacts Session, June 1. "Treatment of a Suite of Baroque Revival Style Seating Furniture by Genevieve Bienisoek, Biltmore
There’s a growing body of publications which detail the features of well-provenanced period upholstery. Such case studies are extraordinarily important for comparison when one is examining upholstery layers on historic seating furniture. In this presentation, Genivieve Bienisoek walked us through her examination and treatment, working together with Anne Battram and Nancy Rosebrock, of a chair and settee from a suite of 12 chairs and 2 settees.
This was one of a number suites which were purchased or produced to furnish Biltmore, a 250 room house built by George Washington Vanderbilt III, completed 1895, and opened to the public in 1930. The pieces in this group of seating are ornately carved, in the style of Italian sculptor Andrea Brustolon (1662-1732), and covered with an embossed velvet, referred to as gauffrage. This particular fabric has a linen ground with a wool pile, and was fairly coarsely woven. The design in the velvet was created with a hot roller pressed into the nap. Apparently this was a popular pattern which was once quite common and produced in France, Great Britain and the United States by a number of companies. Though the fabric had originally been bright gold in color, it looked grey-green due to fading and color shift. Genivieve took note of a second fabric – an unstamped wool plush which was used in less visible places, such as under the arms. This fabric was also gold in color but had a thicker pile and a tighter weave. Both fabrics appeared to have been used originally on the chair and settee as no extra nail holes were noted during de-upholstery of the seating furniture.
More than half of this suite had been re-upholstered in 1976, according to the records, when they were placed in Biltmore’s Music Room. One chair has been left untreated for future reference and research.The aim of this treatment was to return the chair and settee to return them to a nearly new appearance.
Genevieve also made mention of some other features of the chair and settee. Removable pieces of the chair were held with spring clips and slots and screws. The entire back panel of the settee is removable, held in place with turn buckles. The mortises for the arms were slightly larger than necessary to allow for shimming to adjust the level of the ams, ensuring they were horizontal.
After documenting the various upholstery layers and fasteners, she used chalk to track where nails had been removed, and compared it to the show cover, to ensure there had been no empty nail holes. She filled flight holes and other losses in the frames, and inpainted scratches. Re-using existing tack holes, a new linen layer was applied over the exposed original upholstery layers, to a act as an isolating layer against the new show cover and to act as a sewing base.
To ensure that new holes won’t need to be added in future campaigns, she added staples around the spring clip plate to provide a stronger means of attachment of this linen cover. Future campaigns are sure to happen sooner than they might otherwise since Biltmore has no climate control and it is not uncommon for windows to be opened in the house. Everything gets handled and cleaned regularly.
Polyester batting was added to the front of the seat to re-establish the proper shape.
The reproduction show cover was woven by the French firm Prelle. They had the pattern for the gauffrage in their archive. On seeing the reproduction fabric, Genvienve noted that there are actually three levels of stamping in the fabric, adding detail and depth to the design. These details were also in the original fabric, but were difficult to see because of the dirt.
The show cover was stitched to the linen isolating layer with curved needles. Though the trim was originally applied with hide glue, Genievieve used a hot melt adhesive to adhere the reproduction trim, obtained from Heritage Trimmings in the United Kingdom.
If you’re like me, you’re looking forward to the published version of this presentation, which, I’m sure, will be complete with images of the hardware and schematics of the various upholstery layers.
AIC 41st Annual Meeting – Research and Technical Studies Session, May 31, “Artificial Aging of Paper-Based Cores Wrapped in Various Isolating Layers for use as Archival Storage Supports by Amy Williams and Catherine H. Stephens”
When faced with a budget dilemma for oversize mining maps storage, Amy Williams, project conservator at the University of Pittsburgh, asked herself “the $13,500 question:” Is there a benefit to using an archival 12” diameter storage tube core versus a non-archival 12” core wrapped with an isolating layer?
It would be easy to assume that archival cores were significantly better, well worth the extra $13,500. However, when faced with the substantial cost difference, Williams decided to conduct a scientific research project to determine the most cost-effective and preservation-friendly rolled storage system for the 5’ by 15’ maps of the Consol Energy Mine Map Preservation Project. She and her co-investigator, Dr. Catherine Stephens, presented their results on May 31, 2013 during the Research and Technical Studies Session of the AIC annual meeting.
If Williams and Stephens could prove that there was an acceptable, more affordable alternative to archival tubes, the news would be of great benefit to cultural institutions, collectors, and conservators. I was eager to hear their results.
Williams partnered with Stephens, Senior Research Scientist at the Art Conservation Research Center, Carnegie Mellow University (now at Yale University) for the investigation. They studied four types of tubes and six wrapping options suggested by conservators: no wrapping, polyester film, Tyvek, Marvelseal 360, heavy weight aluminum foil, and tissue paper buffered with 3.5% calcium carbonate. For the cores, they selected two archival tubes with different adhesives (sodium silicate versus a blend of polyvinyl alcohol and polyvinyl acetate), a non-archival core of kraft paper with an unidentified adhesive, and a Quik-Tube concrete pouring tube composed of recycled paper and a polyvinyl acetate/acrylic adhesive.
In the experiments, the maps were simulated by using Whatman #1 filter paper. The use of Whatman #1 paper versus historic papers was discussed in another 2013 RATS talk by Bill Minter and John Baty, “The Role of Polyester Film Encapsulation—With and Without Prior Deacidification—On Paper Degradation, Studied During Long-Term, Low Temperature Aging.” Minter and Baty chose historic papers for their research. I think it would add to our understanding if Williams and Stephens conducted a second phase of their research using commercially available papers or naturally aged historic papers to compare with the Whatman #1 results.
Their test samples, each consisting of a “map,” an isolating layer (or none), and a core, were aged at 90˚C and 50% relative humidity in an oven for up to 24 weeks.
The researchers’ first discovery was the unexpected impact of the adhesive, which caused staining on the tubes at the seam gaps between the narrow strips of paper comprising the tubes. This staining transferred onto the Whatman paper “maps.”
To prevent this problem, Williams recommended obtaining seamless tubes by asking the manufacturer to skive the edges of the paper. She also emphasized the importance of knowing the composition of both the paper and the glue of the cores.
I wonder how problematic the adhesive would be during a natural aging process or during a lower temperature artificial aging, and hope the researchers will consider exploring this in the future.
Williams and Stephens reported that the linen ties on the samples caused staining during the aging process. They switched to rare earth magnets, which caused no reported problems. Would a lower temperature during testing have prevented or reduced the problem with the linen ties? If this is a significant problem at all temperatures, linen ties may not be appropriate for rolled storage.
The experiment produced more unexpected results. The researchers evaluated the effects of the cores and isolating layers on the “maps” by measuring the chain scission of the cellulose, the yellowness, and the pH of the “maps.” I was surprised to learn that both the Tyvek and the Marvelseal 360 actively promoted degradation, yellowing, and a lower pH.
The aluminum foil, polyester film, and buffered tissue offered varying amounts of protection, depending on the type of core used. The best isolating layer overall was the heavy weight aluminum foil, and the best wrapper for the kraft tube was polyester film.
I wondered if the high temperature during aging might be responsible for the poor performance of the Marvelseal and the Tyvek, and whether the heat caused chemical changes within these two films. How much of the unexpected results overall was caused by the elevated temperature? Would similar results occur during natural aging at room temperature?
The researchers did speak about this issue. Stephens said that they chose the high temperature for artificial aging to ensure detectable changes, and stated that more research was needed lower temperatures.
From what I understood about the test results that Williams and Stephens presented, it seemed that wrapping a non-archival core with heavy weight aluminum foil could give comparable results to using an archival core. I would like to know more the amount of difference they saw, and hope they will offer a detailed discussion of this in their article about the research.
The results of their experiment have caused me to question my own assumptions about the storage materials we use. I hope Williams and Stephens will continue their valuable research, to determine what results are typical at lower temperatures and answer some of the other questions they raised during this first phase of the investigation.