Category: Research and Technical Studies

Posts on research, materials & techniques used in and by conservators

Call for proposals in Heritage Science for Conservation

Andrew W. Mellon Postdoctoral Fellowship
Heritage Science for Conservation
Call for Proposals
Johns Hopkins University
Sheridan Libraries and Museums

Johns Hopkins University is pleased to announce that it is now accepting proposals under its 2013 call for proposals in Heritage Science for Conservation (HSC).  Supported by a grant from the Andrew W. Mellon Foundation, HSC is an interdisciplinary program based in the Department of Conservation and Preservation of the Sheridan Libraries and Museums which partners with the Whiting School of Engineering’s Department of Materials Science and Engineering at JHU.

Heritage Science for Conservation provides a bridge between the work of scientists and conservators by bringing them together in one lab in order to conduct research, to engage in collaborations with conservators, scientists, students, and industry; and to explore various topics in the preservation and conservation of book and paper collections found in cultural institutions.   By attracting outstanding scientists to the discipline of conservation and uniting scientists into the larger conversations of the heritage community, HSC advances knowledge of conservation of cultural heritage materials and develops the next generation of conservation scientists.

Proposals should seek to combine different scientific and engineering concepts and/or technologies in order to yield new understanding or practical results helpful to conservators. HSC accepts proposals based on the six Research Areas and the corresponding Project Topic. Applicants should refer to the Research Area chart via the following link: http://www.library.jhu.edu/bin/m/h/HSCResearchAreas.pdf

Any research topic from the six Research Areas will be considered. Areas with particular emphasis for HSC include paper strengthening, permanence of coatings and paper sizing, leather consolidants, modeling and forecasting for book and paper aging and degradation, and proof of concept for technology benefiting book and paper conservators, sufficient for commercialization.  In addition to the primary research proposal, fellows will participate in other small avenues of research exploration or develop smaller research initiatives as may be revealed through the course of the primary research project or in the course of working alongside scientists, conservators, curators and industry partners.

Candidates must hold a PhD in a scientific discipline and have a high level of scientific achievement combined with a strong interest in cultural heritage collections.  Experimental research experience and an ability to plan and execute research are required. Salary for the position is $56,000.00 and includes fringe benefits and the health insurance premium.

Please visit our website for further information on the postdoctoral fellowship, the Proposal Guidelines, and the Submission Form:
http://www.library.jhu.edu/departments/preservation/hsc/application.html

Johns Hopkins University is an equal opportunity/affirmative action employer committed to recruiting, supporting, and fostering a diverse community of outstanding faculty, staff, and students.  All applicants who share this goal are encouraged to apply.

Deadlines
·        Submission Deadline:  February 15, 2013
·        Phone Interviews:  March 15, 2013
·        Award Notification:  April 15, 2013
·        Start Date:  August 15, 2013

Call for Papers: Heritage Wood – Research and Conservation in the 21st Century

Joint Interim Conference of three ICOM-CC working groups:

Wood, Furniture, and Lacquer
Scientific Research
Sculpture, Polychromy, and Architectural Decoration

National Museum in Warsaw, Poland
28-30 October, 2013

Hosted in collaboration with the National Museum in Warsaw, and the Academy of Fine Arts in Warsaw

The conference entitled “Heritage Wood: Research and Conservation in the 21st Century ” will focus on novel scientific methods and applied research into heritage wooden structures, as well as furniture, wooden sculpture, painted wood, gilded wood, varnished wood, lacquered wood, paintings on wooden supports, and all other heritage wooden objects.

Themes will include:

  • Advances in scientific research applied to heritage wood for analysis and conservation
  • The study and elucidation of mechanisms of wood damage and wood deterioration associated with environmental and physical conditions
  • The interrelation between the wood and various finishing layers
  • Novel conservation methods applied to unvarnished, varnished, polychrome, or gilded wood (sculptures, paintings on wooden supports, furnishings and furniture, architectural structures and decorations)
  • Case studies highlighting problems associated with heritage wood conservation, novel solutions and appropriate treatments
  • Case studies emphasizing complex research of artworks on wooden supports linking technical investigations with historical context and subsequent conservation treatment

The meeting will provide a forum for discussion between conservation scientists, researchers, educators and practising conservators. The conference aims to bring together international experts on heritage wood research and to provide a great opportunity for the worldwide conservation community to exchange new research, experiences and expertise.

It is the intention of the organizers to publish all accepted papers in English, however oral presentations at the conference will be allowed in both official languages of the meeting, Polish and English, and simultaneous translation will be provided.

Call for Papers deadline: February 28, 2013

Original papers are invited for submission to focus on case studies and advances in heritage wood research. Authors interested in presenting a paper or poster should submit an abstract (400 – 600 words) by February 28, 2013, to     heritagewoodconservation2013 [at] gmail__com

Work should be original and not have been published previously. Contributions of work-in-progress are also welcome. Abstracts should be in English or Polish and include the contact information for the author(s) (affiliation, address, telephone, fax and e-mail). The abstracts will be reviewed by the Conference Organizing Committee and invited experts, and authors will be informed by April 30, 2013.

The Conference Organizing Committee:

Kate Seymour
Coordinator, ICOM-CC Sculpture, Polychromy, and Architectural Decoration Working Group
k.seymour [at] sral__nl

Austin Nevin
Coordinator, ICOM-CC Scientific Research Working Group,
austin.nevin [at] ifn__cnr__it

Dr Malgorzata Sawicki
Coordinator, ICOM-CC Wood, Furniture, and Lacquer Working Group
margaret.sawicki [at] ag__nsw__gov__au

Marcin Draniak
Coordinator–contacts with the Director, Head of Laboratory, National Museum in Warsaw
mdraniak [at] mnw__art__pl

Dr Elzbieta Pietrusinska-Pilecka
Art Science and Conservation Specialist
National Museum in Warsaw
epilecka [at] mnw__art__pl

Dorota Ignatowicz-Wozniakowska
Head of Conservation Department,
National Museum in Warsaw
dignatowicz [at] mnw__art__pl

Prof. Iwona Szmelter
Faculty of Conservation and Restoration of Works of Art, Academy of Fine Arts in Warsaw
badania [at] asp__waw__pl

IRUG Raman Spectroscopy Two-day Workshop

The Infrared and Raman Users Group (IRUG) is pleased to announce a two-day Raman Spectroscopy Workshop to be held at the Philadelphia Museum of Art (PMA) on September 27-28, 2012. The workshop is the first of its kind to be offered by IRUG (www.irug.org) and will feature lectures on practical issues and strategies in the Raman analysis of cultural heritage artifacts and materials, as well as an introduction to the IRUG Raman spectral database. Topics covered will be: the history of the use of Raman spectroscopy in the museum field; theory and instrumentation; SERS; and analysis of minerals, pigments, dyes, gems, glass, plastics, paintings, photographs, works of art on paper, and cross-sections. All are invited to attend although space is limited. Workshop registration fee is $75 for professionals and $35 for students. The registration deadline is August 31, 2012. For more information, please contact IRUG at . The Workshop is being sponsored by the National Center for Preservation Technology and Training (NCPTT) and the Philadelphia Museum of Art. Register >>

AIC’s 40th Annual Meeting-May 11, 2012 Joint Session: Book and Paper Group/Research and Technical Studies, with the Archives Conservation Discussion Group and the Library Collections Conservation Discussion Group “Mass De-Acidification Today”

The session was a series of short presentations by the panelists followed by a question and answer session that was open to the floor as well as pre-submitted questions from the AIC membership.

The panelists were: James Burd, President and CEO of Preservation Technologies, LP; Michael Ramin, Project Manager Research/Analytics, Nitrochemie; Dick Smith, owner Wei T’o Associates; Fenella France, Chief, Preservation of Research and Testing Division, Library of Congress; Nora Lockshin, Smithsonian Institution Archive on behalf of Anna Friedman, Conservator, National Archives and Records Administration.

The first presentation by James Burd “Bookkeeper Deacidification: The Chemistry Behind the Process” began with a review of Preservation Technologies’ twenty years in business, including an overview of their products and services as well as the scope of their operations.  Mr. Burd spent the most time describing the Bookkeeper process, that it is a non-toxic, non-flammable, non-VOC, odorless process that does not use solvents or produce effluents.  The alkaline agent is magnesium oxide (MgO) and in the mass-process it is delivered in an inert suspension liquid in which the books are immersed, relying on an electrostatic attraction to cellulose to deposit the MgO in the paper.  Mr. Burd referenced recent research at the Canadian Conservation Institute and assorted technical studies at the Library of Congress in support of the effectiveness of the Bookkeeper process and reminded the audience that whatever the challenges presented by brittle collections, the greatest risk is doing nothing.

Michael Ramin followed with his talk “Durability, Quality Control, and Ink Corrosion Treatment with the Papersave Swiss Mass De-Acidification Process”.  Papersave is a solvent based process using hexamethylene disiloxane (HMDO) as the solvent and magnesium as the alkaline agent.  For treatment, the books are placed in metal baskets, which are then placed in a chamber for pre-drying, treatment, post drying and re-conditioning.  Papers, books and drawings can be treated by this process.  The items are treated in a vacuum chamber which ensures saturation by the treatment solution followed by the reconditioning process which allows moisture back into the chamber and the moisture in the air activates the deposited alkaline reserve.  The company performs regular quality control in line with the German Institute for Standardization (DIN) and has retained 12 years’ worth of data including surface pH and XRF measurements to determine distribution of alkaline reserve.  Papersave also has sample sets for real time ageing at five and ten year intervals.  According to Mr. Ramin, the Papersave process is alos safe for paper that has iron gall ink corrosion since “through the treatment the acid is neutralized without removal or migration of the ions, on the contrary some of the iron is bound and neutralized.”

Dick Smith’s talk “Wei T’o Paperguard: Comprehensively De-acidifying, Stabilizing and Strengthening Paper” was third in the line-up although all the presenters acknowledged Mr. Smith as a foundation researcher and advocate for the mass de-acidification of paper.  The original Wei T’o product was one of the first on the market for the treatment of acidic paper and Mr. Smith spent a portion of his talk describing how he became interested in the science of paper de-acidification, explaining that even though a piece of paper is thin, penetrating the surface with an even distribution of an alkaline agent is not an easy task to accomplish, especially 30-40 years ago when the technology was not very advanced.  Mr. Smith then went on to profile a new Wei T’o product, still in the development phase, called Paperguard which not only de-acidifies, but also protects paper from fungal growth and pests.  It is a zinc-based process that is environmentally sustainable since the by-products of the process are recoverable.

The fourth presentation was by Fenella France “Taking the Measure: Treatment and Testing in Mass Deacidification” and started with a review of the Library of Congress’ research into the mass de-acidification process which began in the 1970’s and expanded in the 1990’s.  While the Library of Congress has vast historical collections, they are also still taking in acidic collections from all over the world and their current mass de-acidification treats more late 20th and early 21st century books from India, Spain, USA, etc. than 19th century material.  The initial goal for the Library’s research was to establish a process that would deposit an alkaline reserve that tripled the longevity of an item, Bookkeeper was selected and a treatment facility was installed on-site at the Madison building.  Testing and quality control is ongoing, but Ms. France sees a real need for the library research community to do more independent testing and not rely on vendor sources since there is too much variation in test methods to allow for meaningful comparison of data.  A single measure that could be applied across the different mass de-acidification processes would enhance the assessment process and allow for agreement on the definition of progress.

The final presentation was Nora Lockshin on behalf of Anna Friedman “Evaluating De-Acidification After 20 Years of Natural Aging”.  Ms. Friedman’s research focused on a treatment group from a 1989-1991 project at the Smithsonian Institution Archives where over 500 architectural drawings out of a record group of over 2,000 were sent out for de-acidification with Wei T’o Soft Spray or an aqueous bath with Magnesium Bicarbonate.  Ms. Friedman used surface pH testing and colorimetric measurements at 5 points across the front of a drawing to evaluate the long term effectiveness of the de-acidification treatments.  The colorimetric evaluation did not show any trends, but the surface pH showed that the application of Wei T’o was very uneven across the surface of the document.  This would make sense given the application process of Soft Spray.  However, comparison with a control group showed that documents that had been treated for mass de-acidification did have a higher pH after 20 years of natural aging.

The open discussion that followed began with a submitted question

SubQ: Is spraying of individual items as effective?

A: Papersave and Paperguard cannot be applied singly- mass only

Q: (Emily Rainwater) As a user of post-Bookkeeper treated items, she finds a lot of residue from handling the books, e.g. turning pages.

A: (Burd)- The particulates should go away as the treated book ages. (France)- Early in the development of the Bookkeeper process the particles were fairly large; they’re smaller now, so the white powder problem should go away.

Q: (Eric Hansen)- Italian conservators and others have complained that Bookkeeper changes the feel of the paper.  Will Bookkeper address this question in a direct way so that this issue can be settled?

A: (Burd)- People really shouldn’t be able to tell, he has spray with him and offered to let people spray samples of paper and feel for themselves.  The particle size is small and the quality control protocol of mass de-acidification is rigorous.  (Smith)- Is particle size really the issue? Are we measuring what we think we’re measuring in terms of quality control? The TAPPI tests that we generally use are a standard, but are not precise to our need.

Q: (John Batty)- What does Mr. Burd mean by “pure” alkaline reserve?

A: (Burd)The magnesium that Bookkeeper uses is of high purity, but also there is no residue of other treatment fluids after the process is completed since the Bookkeeper process is full recovery.

Q: (John Batty)- To Mr. Smith: are you planning to treat artist’s materials to a specific pH?

A:(Smith) Not just to a specific pH, but also using zinc to ensure fungal and pest prevention.

Q: (Johanna P) To M. Burd, how is the benefit to ink measured, given that iron gal ink is supposed to stay acidic? Also, what about the color change or yellowing of treated items?

A: (Burd) If you have an ink you want to stay acidic, don’t treat it with a de-acidification process.  If you want to stabilize iron gall ink and protect the substrate as well, then the Bookkeper process can be directed toward strengthening of paper.

A: (Ramin)- Non aqueous is better treatment since the paper is not as stressed.

A: (Smith): Commenting on paper yellowing after treatment by Wei T’o; he took yellowing as a sign of effectiveness since it demonstrated penetration of spray (this was in the early days) but don’t give up on de-acidification, work on delivery of the alkaline reserve.

A: (Burd)- Commenting on yellowing- Since the Bookkeeper process doesn’t use a solvent, there shouldn’t be any yellowing.  Some researchers have spotted yellowing due to aging of magnesium, but Burd thinks the books would probably have yellowed anyway, so the magnesium application just changes the characteristics of the yellowing. Burd went on to comment that yellowing is only present in artificially aged paper samples, and that 20 years is not long enough for real time aging to be conclusive.

A: (Ramin) Papersave tests show some yellowing in ground wood and to comment on mold remediation, the Papersave drying process kills mold, which is a side benefit.  Once treated, collections tend to have better storage conditions, so mold is less likely to grow again

A: (Smith)- Zinc has potential for mold and pest prevention in addition to mass de-acidification.

A: (Burd)- Alkalization does help with mold prevention

Q: (Ursula ?): Could there be more natural aging studies? To Ms. France, given ten years of using Bookkeeper, are you doing any studies? To Ms. Lockshin: were the treated papers stored differently?

A: (France)- Yes, the Library of Congress is initiating a long term study.

A: (Lockshin) all treated drawings were encapsulated and then opened for analysis but were otherwise stored together.

Q: (Cathleen Baker): the audience knows a lot about the complexity of paper, but the ads and trade lit is a little unsophisticated and implies that mass treatment should be readily applied, whereas selection is a more complex process.  What about the effect of mass de-acidification on lignin?

A: (Burd)- This has been reported in literature, but if you attack lignin you will make paper weaker, to prevent this effect, don’t select items that are brittle where the lignin or cellulose is already weak, they can’t be rebuilt by mass de-acidification.

A: (Lockshin) Commented that the Smithsonian receives many reference calls, people have seen an ad for a product and want information on its effectiveness.

Q: (Renate Mesmer) The Folger Library has just started a Bookkeeper project and wanted to comment that handling of books for the Bookkeeper process is extreme, given the fanning out and agitation.  They have also found very high amounts of white deposits, and given these high amounts of surface deposits, is anything going to the core of the paper?

A: (Burd)- Since we don’t use solvents we have to fan the books so that the alkaline particles can make their way into the paper.  If a book is too delicate for the mass process, then use the single item process. Distressed to hear that there are a lot of white deposits.  Porosity of the paper is the dependent factor on penetration, but acids migrate toward the alkaline particles so this shouldn’t ultimately be a problem.

AIC’s 40th Annual Meeting – Paintings Session, May 9, “Frederick Hammersley: An Artist’s Documentation of His Painting Practice” by Alan Phenix

Pacific Standard Time is not just a time zone.  It is also the title of a Getty-funded initiative, jointly launched by the Getty Foundation and Getty Research Institute, that enabled more than sixty cultural institutions across Southern California to tell the story of the art scene in Los Angeles, California.  The initiative focuses on archives, research, exhibitions, publications, and other programs to record the region’s artistic history.  A substantial part of the project is dedicated to Los Angeles art from post-World War II through the 1970s.  In 2011/2012 The Getty Center held an exhibition entitled Crosscurrents in L.A. Painting and Sculpture, 1950-1970.  One of the artists in the show was the painter Frederick Hammersley, who died in 2009.  After Hammersley’s death a artist-endowed Foundation was established to preserve and maintain his artistic legacy.  Getty researchers first encountered the extensive archive of materials held by the Hammersley Foundation during preparations for the Crosscurrents show.  Alan Phenix presented to the Paintings Specialty Group some introductory observations on the wealth of that information.

Frederick Hammersley was a leading abstract painter in Southern California in the postwar period.  He first gained widespread notoriety in 1956 when he was included with artists Karl Benjamin, Lorser Feitelson, and John McLaughlin in an exhibition entitled Four Abstract Classicists.  The show led to the coining of the painting movement known as “West Coast Hard-Edge”.  Hammersley was born in 1919 and studied art in the 1940s at the Chouinard and Jepson Art Institutes in Los Angeles.  He stayed on at the Jepson Institute in a teaching capacity after he finished his studies.  He also held subsequent teaching positions at Pomona College (1953-62), Pasadena Art Museum (1956-61), and Chouinard (1964-68).  In 1968 he took a teaching position at the University of New Mexico in Albuquerque, which he kept until 1971 when he stopped teaching to concentrate on his painting.  He continued to work at his home studio until six months before his death and his space remained essentially untouched after his death, serving as final documentation of his life and work.  Hammersley had also fastidiously documented his artistic process in series of notebooks for a period of more than 50 years with few interruptions.  Among the most notable of these were four “Painting Books” that consist of cumulative and descriptive chronological lists of works completed.  The project being undertaken by the Getty Conservation Institute aims to examine and interpret that archive of materials for what it may reveal about Hammersley’s process, materials and techniques, and what it might mean for the preservation and conservation of his work.

Hammersley’s painting had a strong psychological element, which is illustrated in the evolution of his work.  From 1954 to 1959 he worked on a series he called “Hunch” paintings, which developed without preparation as the artist relied on “hunches” coming from reflection and intuition to guide his work.  In 1963 until 1965 he worked on series defined as “Organics” and “Cut Ups” that expanded upon his intuitive painting with more organic processes.  In several periods throughout his career he also worked on more hard-edged geometric paintings.  An early instance of his documentation and creative evolution was found in a set of notes on labels on the back of a 1956 “Hunch” painting entitled In Front Of, in which he recorded dates for the addition of specific shapes in the composition.

The artist began keeping his “Painting Books” in 1959, wherein he kept lists of his work, information about his process, when and to whom each work was sold, and other related information.  The details of his records continued to increase and by 1966 he’d expanded his notes to include additional items, such as information on specific paints.

It was interesting to hear that Hammersley’s documentation was not limited to formal records and itemized lists; his notebooks were also works of art in their own way.  Some of his books contained visual composition ideas in thumbnail sketches.  When he liked a composition he would execute it in a slightly larger (ca. 3″ x 3″) format.  Eventually he began including sequential breakdowns of the development of particular artworks.  On occasion he would revisit past artworks and those changes were also documented in his notebooks.  The artistic process was not limited to the works themselves.  Hammersley kept a “Titles” folder that contained lists of words written by free association.  When he came across words he liked he would underline them and then retrofit them to create titles for particular works.

This presentation just scratched the surface of the available information in Hammersley’s personal documentation.  The goal of the Getty Conservation Institute’s work is to make the mass of information of Hammersley’s archive available to a wider audience, including conservators who may have cause to work on his paintings in the future.  A searchable database is envisaged once the material is transcribed, collated, and interpreted.

This year’s annual meeting was focused on connecting to conservation through outreach and advocacy.  A searchable database of artists’ materials and techniques certainly has potential to assist with that effort.

AIC’s 40th Annual Meeting – Paintings Session, May 9, “Relating Artist Technique and Materials to Condition in Richard Diebenkorn’s ‘Ocean Park’ Series” by Ana Alba

When Ana Alba was working at the Hirshhorn Museum she undertook a research project on four paintings from Richard Diebenkorn’s “Ocean Park” series.  Her study compared the materials used in each of the paintings and assessed how that tied in to their current condition.  She presented her findings at the 2010 annual meeting in Milwaukee, Wisconsin.  Two of the paintings had severe cracking while the other two were in good condition; the paintings with the cracking had an acrylic preparatory layer.  At this year’s annual meeting she presented research conducted at the National Gallery of Art that expanded upon her intial study.

Ana’s current research involved the examination of more than 45 paintings and samples for analysis were collected from approximately 15 paintings.  All of the information gathered was compiled into an extensive chronological database.  An additional list of travel histories with photographic references was completed.  The results of this study showed changes in the artists materials both between paintings and within individual works.

Diebenkorn worked for weeks to years on some of his paintings.  He painted consistently on unsized cotton duck but his choice of preparatory materials fluctuated over time.  Between 1968 and 1973 he used white acrylic gesso and toned it with diluted acrylic.  In some cases he added alkyd.  From 1973 to 1978 he transitioned from white to clear preparatory layers, presumably in order to maintain the raw canvas color and achieve transparencies in his paint layers.  Scientific analysis suggested the clear material was synthetic and consistent with Rhoplex AC-33.  This was more or less confirmed by photographic evidence of showing large jugs labeled as Rhoplex located in the artist’s studio.  By 1979 Diebenkorn had returned to using acrylic gesso almost exclusively.

Diebenkorn primarily painted with acrylics and alkyds.  He added oils sparingly and extended his paints as far as possible.  He also used charcoal, graphite, and colored pencil to define his images.  Infrared reflectography of his paintings show numerous alterations in his compositions, which is unsurprising given his appreciation of layering and the amount of time he spent working on each piece.  Once a painting was finished he applied matte fixative to the surface.  In his early works he applied this in 6 or 8 consecutive layers that left a glassy, heavy surface.  Eventually he shifted his process and masked out the painting to limit application to the charcoal areas.

The condition assessment of this larger group of paintings seem to support the findings of Ana’s initial study.  Paintings executed between 1960 and 1973 vary and some show some cracking.  The cracks follow drawn lines, compositional changes, and are greatest on the paintings with heavy layers.  Paintings completed after 1973 and before 1980 have heavier, more pronounced cracking with broad and isolated areas of cupping.  These paintings follow the same trend as the earlier works with the greatest cracking located in the layered areas.  Diebenkorn’s paintings after 1980 are in much more pristine condition with less cracks.  The trend of this condition timeline show that the paintings in the poorest condition are located in the middle of the Ocean Park series.  This supports previous findings by showing that paintings with Rhoplex and acrylic exhibit the worst cracking, especially when they are painted thickly with numerous layers.

This study highlights concerns regarding some of Diebenkorn’s selection of materials.  Alkyds are brittle so putting them over flexible preparatory films and unsized canvas makes them susceptible to cracking from impacts and physical movement of the substrate.  Fortunately, they do not seem prone to delamination so the cracking does not lead to significant paint loss.  In addition, when Diebenkorn diluted his materials he reduced their strength.  That left them with a greater chance of deformation in response to physical and environmental factors.

Ana pointed out that there are some limiting and extenuating factors to consider in this research.  The are as follows:

  • No samples were taken from privately owned paintings.
  • His assistants did not see him working so they could not provide information about his process
  • Diebenkorn did not keep detailed records of his work or do preparatory drawings.
  • The study compares paintings in good and poor condition only.
  • The artist destroyed some works, painted over others, and skipped #5 when creating the series.
  • One large painting from Brooklyn was an outlier in the study; it was completed prior to 1973 but it shows significant cracking across large ares of the surface.
During the question and answer session following the presentation it was also noted that areas with Rhoplex on raw canvas showed discoloration.
I have a personal appreciation for Diebenkorn’s work and have enjoyed following the progression of Ana’s research project.  By coincidence, I had the opportunity to realize that interest in person this week when the exhibition, Richard Diebenkorn:  The Ocean Park Series, was deinstalled at the Orange County Museum of Art in California.  I conducted outgoing condition assessments of some of the paintings and was able to see exactly what Ana had discussed in her presentation.  The exhibition will open at its final destination, the Corcoran Gallery of Art, on June 30th.  I encourage all of you to check out the show if possible to see the subjects of Ana’s research side by side for the first time on such a large scale.

AIC’s 40th Annual Meeting, Objects and Research and Technical Studies Joint Session, May 9, “The Qero Project: Conservation and Science Collaboration over Time,” by Emily Kaplan et al.

Emily Kaplan (Presenter), Objects Conservator, Smithsonian National Museum of the American Indian; email: kaplane@si.edu

Ellen Howe, Conservator, Sherman Fairchild Center for Objects Conservation, Metropolitan Museum of Art; email: ellen.howe@metmuseum.org

Ellen Pearlstein, Associate Professor, Conservation of Archaeological and Ethnographic Materials, UCLA; email: epearl@ucla.edu

Judith Levinson, Director of Conservation, Division of Anthropology, American Museum of Natural History; email: levinson@amnh.org

The qero research project is a seventeen-year-long collaboration among object conservators at four museums with qeros in their collections: the American Museum of Natural History (AMNH), the Brooklyn Museum, the Metropolitan Museum of Art (MMA), and the Smithsonian’s National Museum of the American Indian (SI, NMAI). Emily Kaplan (SI, NMAI) presented an update of the research to date on behalf of her co-investigators, Ellen Howe (MMA), Ellen Pearlstein (formerly Brooklyn Museum, now GCI-UCLA), and Judith Levinson (AMNH). The project is an in-depth technical study of materials and techniques of fabrication of a corpus of qeros, polychrome wood drinking vessels fabricated around the time of the Spanish conquest of Peru in 1532; the qeros in these four collections date from the Inca period (13th-15th c.), through the Colonial period (16th-19th c).  Consequently, the qeros offer material culture insights produced over a span of centuries and reflect the influences of both indigenous cultures and Spanish colonizers.  Principal goals of the project involved: understanding techniques of fabrication, the analytical identification of materials, and the correlation of the technical data with the stylistic data proposed by others (i.e. curators, art historians).

The qero project was an apt presentation for the joint OSG-RATS  session. Kaplan articulately presented the cultural history of the vessels, as well as the technical research undertaken by numerous conservation scientists, principally at the Boston Museum of Fine Arts and at the Metropolitan Museum of Art.  Indeed, both cultural and scientific research were presented in nearly equal measure, which underscored the efforts of the primary researchers to cover both aspects in depth.  Efforts at replication of techniques of manufacture, cultural exchanges with colleagues and artisans in Peru, and the application of the full arsenal of analytical  methods employed (including FTIR, GC-MS, PLM, XRD, and XRF) were discussed.  Kaplan noted that YouTube videos exist showing contemporary Columbian artisans in Pasto working with the sheets of resin.  The presentation was accompanied by quite beautifully photographed images of the vessels themselves, comprised of tropical woods with polychrome resinous inlays, which illustrate geometric (Inca) and figural (Colonial) design registers of increasing complexity.

Funding from the MMA and NMAI allowed Kaplan and Howe to travel to Peru to meet Andean artists and scholars; to collect raw materials; and to visit private and public collections.  Eventually botanical samples of the plant elaeagia were correlated via FTIR and GC-MS to the mopa-mopa resin noted in early literature and the samples from qeros.  Interestingly, the palette was identified as largely unchanged from the pre-Colonial period.  Colorants identified include cinnabar red, orpiment yellow, cochineal red and pink, indigo blue, copper-based greens, carbon black, lead white and titanium white.  A notable, recent reassessment is the meaning of the analytical identification of titanium white (cristobalite anatase in mineral form) on some vessels.  Early in the project, the noted presence of titanium white—a  pigment that found wide usage only in the 20th century—was  thought to indicate areas of restoration.  Further study focusing on the presence of elaeagia in the media, led the conservators to believe it to be a pre-Colonial pigment.  A known Andean ore does exist.

Current research questions involve study of the ore source(s) of the cristobalite anatase and pigment comparisons to Colonial Andean paintings.  Further, the research and data collection evolved with technological advances and the collaborators are now considering ways to aggregate and share the data on-line.

This research project can be seen as a model for other conservation projects involving multiple institutions.  The sustained curiosity about these objects inspired a prolonged inter-museum collaborative effort , involving international allied professionals.  I’ve followed the progress of the qero project over the years, attending presentations and watching the list of publications in the US and South America grow longer and longer, as new findings emerged.  Near the beginning of the project (which started in 1995), while a graduate conservation student at New York University, I participated for two years as a research assistant on the project.  The concerted efforts to study both historical techniques of fabrication and the scientific results of analytical testing represent for me why the qero project ideally embodies the captivating interdisciplinary aspects of the conservation profession.

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

 

AIC’s 40th Annual Meeting, Objects and Research and Technical Studies Joint Session, May 9. “The Use of Agar as a Solvent Gel in Objects Conservation” by Cindy Lee Scott

Perhaps better known as a medium used in biological studies, agar is gaining traction in the conservation profession as an ingredient for building poultices. The material, a combination of the polysaccharides agarose and agaropectin derived from the cell walls of an alge, is widely available, both in a highly purified form through laboratory supply houses and in a food grade form. It is used as a rigid gel to make poultices for flat surfaces or as more liquid sol-gel for three dimensional surfaces.

Cindy Lee Scott’s study of this material and possibilities for its use in removing shellac from ceramic surfaces was inspired by work using agar gels to clean outdoor plaster busts presented in 2010 by Paolo Cremnesi and published by Anzani et al. In their work, deionized water was the primary ingredient in their poultices, but Cindy Lee wondered if solvents and other cleaning agents could be added to these mixtures to extend their versatility and how these additions might change the stability and working properties of the gel.

After reviewing various properties of the material, particularly the manner in which the porosity of an agar poultice could be modified by altering its concentration, and then the  manner in which the gel is typically prepared, used and removed from a substrate (it peels off the substrate cleanly), Cindy Lee presented her own work, conducted in two phases.

The first phase of her work, a component of her thesis as part of her studies at the UCLA/Getty program, involved exploring agar as a gelling material for various cleaning agents on terracotta test tiles coated with a kaolinite-type slip with the goal of finding new ways to removing shellac from previous restored ceramics. She tested agar sol-gels mixed with ethanol, acetone and 5M sodium hydroxide, alone and in combination. She looked at efficacy of cleaning and clearance using visual analysis using a binocular microscope, UV-fluorescence microscopy, and FTIR spectroscopy.

She found that these agar gels performed beyond expectations particularly in comparison with other options tested for that study. She found that agar sol-gels had excellent working properties when they were mixed with ethanol and sodium hydroxide and had good clearance from the surface. Clearance improved for gels with a lower concentration of agar when Japanese paper was used as an intermediary layer.

The second phase of Cindy Lee’s work, undertaken during her internship at the Museums of New Mexico, extended the number of cleaning agents added to agar gels. Additives included solvents, surfactants, chelating agents, oxidizers, and acids. She noted working properties of each mixture, color changes to the gel that might lead to staining, and stability of the resulting gel. In this phase, access to analytical equipment was limited, so her analysis was generally limited to visual observation. Additionally, these mixtures were applied to plaster tiles coated with various materials including alizarin dye, shellac, various paints, PVA emulsion, and soil and artificially aged to test cleaning and clearance.

To summarize very quickly, as far as adding solvents go, best results for workability were achieved with ethanol, then Stoddard Solvent followed by acetone and xylenes. She noted that solvents added in too high a concentration could cause the gel to dissociate. Good working properties were also noted for gels made with the chelating agents, oxidizers, acids and bases tested. The surfactants tested caused complete dissociation of the gel. As far as cleaning efficacy, it appears that gels tested had a more difficult time removing dye and smaller particulates, but with regard to smaller particulates, concentration of agar within the gel appears to have a great influence. She found that efficacy could be improved by altering concentrations of agar and solvent, the temperature of the poultice on application, the length of application and number of applications of the poultice.

Cindy Lee concluded her presentation with  pros and cons of using agar-based solvent gels for objects conservation. Since she was kind enough to provide me with her paper and slide deck to help me write this post, I will share them here (if you click on the image it expands):

In short, I found her presentation to be an excellent introduction to this material and I can’t wait to experiment with it myself. It was also excellent to see the kind of simple testing we all do regularly in our own labs presented in a RATS/OSG session, and I look forward to seeing this work published. I don’t presently use Agar, but her presentation has encouraged me to do some experiments to see if this material would be appropriate to use in my own practice.

AIC’s 40th Annual Meeting, Objects and Research and Technical Studies Joint Session, May 9, “A Comparative Study of Protective Coatings for Marble Sculpture in the Museum Setting,” by Laura Kubick

One of the reasons I enjoy joint sessions is the more focused theme and connection between the talks. Laura provided a nice overview of the research that she carried at out at SAAM on marble coatings. Three white marble sculptures in the collection- by Rinehart, Cooper, and Houdon- attract a lot of attention and love from the public. Some love comes in the form of red lipstick. Laura took this as an opportunity to explore traditional and newer materials for coating marble and determine which have the best protective properties.

Her testing methods appeared thought out and well carried out. She tested Cosmoloid 80H wax and Ketone N resin, Renaissance microcrystalline wax, Methocel A4C Methyl Cellulose, and Avalure AC 315 Acrylic Copolymer 5% and 7% in ethanol. She tested polished and unpolished marble. All the coatings were applied by brush. They were tested for their appropriate aesthetic properties, effectiveness as a barrier, safe application and removal, reversibility and aging. Quite a feat if I say so. Needless to say there is more testing that can be done. However, her initial findings are quite interesting. To measure changes in color and gloss Laura used a Spectro Eye spectrophotometer and gloss meter. The marble samples were stained with lipstick, red wine, and a sharpie. Laura provided a nice graphic showing her samples and the order of testing, aging, cleaning, etc.

Overall, from the testing Laura concluded that none of the coatings were perfect. There is a give and take with all. However, most importantly Renaissance wax was NOT a good barrier- I found it shocking that the red wine etched the marble through all of the coatings except Avalure. The wax resin and avalure did the best in the aging test. Methyl cellulose had the best reversibility, while microcrystalline wax was the worst. It was also interesting to hear that the colorimeter readings were consistent with what she observed by eye. Although nothing can replace scientific readings it is nice to know that our trained eyes are good for something. She also felt that more research should be done on methyl cellulose and Avalure since they tested tested so well. Her tests were only done on small samples, but the practicality of applying it to a large sculpture might change things. Avalure is somewhat difficult to work with, but perhaps a spray application would be better. By the way, Avalure is available through the manufacturer and apparently they are generous with their free samples.

I don’t know if this would be possible, but a follow up to this study might be interesting to look at the penetration of these coatings into the marble. Perhaps looking at a cross-section with FTIR-ATR…