AIC's 53rd Annual Meeting

The Victoria and Albert Museum (V&A) has recently implemented a novel lighting policy (discussed in detail in VanSnick & Gaspar, 2024) - seeking to strike a balance between the display of light-sensitive objects and their long-term preservation. This work offers an evaluation of the practical rollout of the policy, refinement of process, and stakeholder uptake.

This policy works by whittling down collection on display to those objects that have the most pressing light vulnerabilities, looking experimentally at those objects, and using that new information to inform how we select vulnerable objects in the future. The first step is determining light vulnerability on a broad material level, flagging objects on display made from materials academically known to be highly light sensitive. These broad strokes are of huge benefit as it ensures that the first action of this policy will target those objects with the potential to be currently undergoing massive light damage. The second phase invites curatorial colleagues to assign a relative value each object in the group of highly light sensitive objects, allowing resources to be targeted in on the most exemplar objects which are materially assumed to be highly light sensitive. Where possible, objects that are highly light sensitive will be rotated out of display in a time period dependent on their rating value. Where rotation is not possible objects are examined experimentally using Microfademetery Testing (MFT).

Objects are unique in their vulnerabilities and these vulnerabilities are not as linear, consistent and predictable as one might expect. Experimentally analysing objects using MFT has the potential to bring their actual current light vulnerability into sharper focus. Given the vast size of the V&A’s collection, it is truly unfeasible to experimentally analyse every object - however this policy allows precise targeting of experimental resources to the places in the collection where they are most immediately needed. The lessons learnt about discrepancies between the assumed light sensitivity and the current experimental reality found are fed back into the initial stages of this process, allowing us to redirect resources to more vulnerable objects. For example, MFT conducted on Chinese, Japanese, and Korean lacquerware as part of this process has found this material to generally be drastically less sensitive to fading in practice than was academically thought. Not only does this mean that these objects can have far greater lifespans on display, improving access and ensuring we are focussing on the collections that need us most. 

This is not a static system - it is a cyclical process that edits and allows a more accurate picture of the collection’s sensitivities to coalesce in each iteration. It allows us to learn about our collection today and to react as the composition and the needs of our collection evolves over time.

The light sensitivity of works on paper is an important issue for any paper-based collection with regular exhibition cycles. The main concern is to protect the media from light-induced color changes, and MFT is a proven in-situ method for predicting these changes. As a substrate, however, white paper and especially rag paper is generally considered to be quite stable, with the exception of wood-containing and colored paper, which are considered light-sensitive according to the lighting guidelines. However, within the broadly defined class of white papers – which have been the most widespread worldwide since their emergence – there are also lignin-free white papers that are affected by moderate exposure to light. Our research group – three conservation scientists and five paper conservators collaborating from a print and drawing collection, a conservation science research laboratory, and two universities – studied typical light sensitivities related to compositions of paper and the ability of MFT to predict light-induced change in a broad range of the most typical white paper compositions.

We prepared nine sets of 37 papers divided into four compositional groups that represent papers across time. Three sets were aged in UV-filtered museum and commercial gallery exhibition-simulated settings (LED, mixed fluorescent/daylight, up to ca. 2.5 Mlxh), four underwent cyclic light-dark aging with or without pre-aging, and two sets were micro-faded by two commercially available MFT devices, one with a xenon source, the other a LED source. Using this test setup, we evaluated the influence of paper components on the color development of the papers during these different natural and accelerated aging conditions and compared them with the MFT results. The color change data of all exposures are given in Blue Wool Scale (BWS) by comparison to co-exposed Blue Wool Standards. 

Most white papers in exhibition simulation fell into the relatively stable BWS 2.5–4, but aged rag papers and papers containing ligneous and OBA papers ranged at BWS 1.–2.5. The predominant color change tended to be fading, but highly optically brightened (OBA) papers of low quality darkened. Groundwood and other high-lignin papers changed to yellowing after initial fading. Iron-contaminated papers without a significant alkaline reserve also tendentially darkened. Previous light-dark aging cycles had an effect on the type of color changes caused by light. Both MFT types and the cyclic light-dark aging predicted the papers’ sensitivity adequately compared to the simulated exhibition exposures and identified the most light-sensitive gelatin-sized rag papers and lignin-containing papers. However, predicting the color change of OBA-containing papers proved to be much less reliable. The color change of the papers that were exposed to LED in the exhibition-simulation was better reproduced by LED-MFT than by xenon-MFT or cyclic light-dark aging.  

We hope that the research results of the recently completed project will provide a clearer idea of the role of white paper in predicting the light sensitivity of artworks on paper using MFT. 

Our collaborative project was funded by the Germany Research Foundation 2021–2024.

Preservation Programs at the National Archives and Records Administration (NARA) investigated the characteristics of iron gall ink (IGI) in low or no-oxygen environments. NARA has vast holdings of 18th,19th, and early 20th century documents with iron gall ink. With the 250th anniversary of the Declaration of Independence, conservators and scientists seek to understand more about long-term display of sensitive IGI documents. In the past, NARA has used sealed anoxic encasements for some permanently-displayed iron gall ink documents. However, recent research into IGI behavior in anoxia [1] as well as material and structural differences between the majority of paper-based documents in NARA's holdings and other treasured national records on parchment meant that the use of a low oxygen display environment needed to be examined. 

Scientist Bruce Ford previously demonstrated that fading of iron gall ink is somewhat reversible in the dark but that anoxia diminished this reversion potential. His experiments exposed ink to light levels equal to several decades of display exposure, followed by a period of darkness that allowed ink to revert overnight. We sought to conduct a similar experiment, but with a closer match between typical exposure and rest periods to exhibit conditions. Additionally, we wanted to know if IGI reversion potential could ever be exhausted or would change with past treatment history. Subsequently, we designed experiments using an automated LED MFT (2700K white LED, ~3.1Mlux) in an atypical manner. We repeatedly exposed 19th century, post U.S. Civil War era, non-record samples and paused for reversion periods in the dark on the same spot. We tracked incremental and overall change in color (ΔE00) and L*a*b* color space parameters. We also tracked and controlled temperature and humidity as much as possible to prevent movement during test periods (up to 1.5 weeks) and kept the dose for each exposure as low as possible (0.04-0.4 Mlux-hrs.), only inducing enough change required for reasonable signal to noise ratios. We performed mock de-silking and delamination treatments on historic samples to mimic the condition of many NARA holdings. Treated ink required higher dosages of light to induce the same amount of change as non-treated IGI. We conducted multiple cycles of low-dose MFT both in air and anoxia and were able to reproduce Ford’s result showing reversion in air, and significantly reduced reversion in anoxia. We investigated the nuances of reversion in each of L*, a* and b* under each condition. After several tests in anoxia, we reintroduced oxygen up to 2% concentration which showed a returned ability to revert. MFT results were also compared to an experiment with 2 klux LED lamps (up to 4.5Mlx-hrs) where no visible change was observed. This indicated reciprocal failure, however these results still have important implications for display design options for iron gall ink records.

Works Cited

1. Ford, B. 2014. “The accelerated light fading of iron gall inks in air, hypoxia and near-anoxia.” In ICOM-CC 17th Triennial Conference Preprints, Melbourne, 15–19 September 2014.

Joe Overstreet (1933-2018) was an innovative artist who defied easy categorization. Interested in art from a young age he studied in California at different institutions but by 1958 he felt he had outgrown the West Coast and moved to New York where he became friends with many of the abstract expressionists and color field painters working there. Always politically motivated, many of his works from the 1960s directly referenced the civil rights movement, some such as The New Jemima(1964) are overtly figurative whereas others, such as 16th Street Birmingham (1963) and Strange Fruit (1965), are more abstract. In the late 1960s, urged by Frank Stella and Sam Gilliam, Overstreet began to create shaped, unprimed canvases painted in acrylic with bold geometric patterns that referenced his African and Shoshone heritage. These works, exemplified by North Star(1968) and Justice, Faith, Hope and Peace, presaged his growing interest in the sculptural possibilities of paintings. In his next, perhaps best-known series of works Overstreet freed himself from the stretcher altogether. His mandala paintings, such as Hoo Doo Mandala(1970), retain the geometric patterns of the shaped canvases but are stretched onto the surface of the wall. His slightly later flight patterns incorporate the soak-stain approaches of Gilliam and Frankenthaler and are held in taut geometric shapes through ropes attached to the walls, floors, and ceiling. Overstreet indicated that his use of ropes referenced both construction techniques used by Ancient Egyptians, and the ropes used in lynchings, while his desire to create easily transportable works was an homage to his nomadic ancestors who survived with our art by rolling it up and moving it all over."The founders of the Menil Collection, John and Dominique de Menil had a long association with Overstreet, purchasing The New Jemimaand several flight patterns. Through this connection he was invited by Larry Rivers to participate in the 1971 Some American Historyexhibition and in 1972 Dominique organized a solo show of Overstreets works at the Rice Institute for Arts. In 2025 the Menil Collection will open Joe Overstreet: Taking Flight,which brings together shaped canvases, mandalas, flight patterns and his seminal late series of oil paintings made after visiting Senegal in 1992. This exhibition, and access to Overstreets artworks and studio materials provided by the Eric Firestone Gallery and Corrine Jennings, Overstreets partner, provided an unparalleled opportunity to begin to examine Overstreets materials and methods. Overstreet said that My work has changed every picture I've ever made, because I'm searching for the unknown truth, but how did his materials and methods change over time? Non-destructive analysis by XRF and limited sampling revealed a shift in pigments, and an increasingly complicated painting process as he moved from shaped canvases to mandalas to flight patterns while his Senegal series marks a return to the use of oils, particularly those of the New Holland line. This is the first in-depth study of this seminal artists practice and helps reveal the various ways he sought to express his truth.

Beginning with his Nocturnes, Whistler began diluting his oil paint with a secondary medium he referred to as his “sauce.” Such a fluid medium allowed the artist to work wet-in-wet, and facilitated scraping, rubbing, and scumbling. While there are primary source references to copal being used in his “sauce,” there have been no technical studies that have identified copal as an ingredient that Whistler employed. In the 1980s and 1990s, Stephen Hackney and Joyce Townsend collaborated on a series of technical studies on paintings by Whistler in the Tate, National Gallery of Art, and Hunterian Art Gallery, among others. Their research did not find any evidence of copal, instead determined that turpentine and mastic varnish were added to the oil paint to create the sauce.

The four Nocturnes in the Harvard Art Museums’ collection (1943.171, 1943.172, 1943.173 and 1943.176) were completed over the course of the 1870s. The paintings are significantly understudied, largely due to their inclusion in the Winthrop collection, which stipulates their continuous display in the galleries and prevents their travel. The closure of the museum during the pandemic provided a rare opportunity to study the paintings. This research aimed to contribute up-to-date material analysis to compare with primary sources and build on the work of both Hackney and Townsend.

A small set of samples were taken from each painting and were either prepared as a cross-section or analyzed by thermally assisted hydrolysis and methylation pyrolysis-gas chromatography mass spectrometry. A comparison of the data has revealed some insight into Whistler’s painting materials and technique for this set of paintings. In darker compositions (1943.171 and 1943.173) multiple layers of media rich paint, some of which were unpigmented and all varying in thickness, were applied. This is in contrast to lighter compositions (or areas, 1943.172 and 1943.176) where single, relatively thick, pigment rich layers were applied. In these layers the addition of organic media was observed, in patches or waves, suggesting incomplete mixing. Pinaceae resin, may at the very least be suggested to be part of Whistler’s ‘sauce’ based on the analysis conducted here. Using written accounts as a guide the use of turpentine could be suggested, which would result in a more fluid paint medium which is a characteristic of Whistler’s paint. Analysis also suggests the recipe for Whistler’s sauce was not fixed, with evidence found for the incorporation of bleached shellac (1943.171) and perhaps mastic (1943.172) into the paint in some but not all of the nocturnes.

The Courtauld Gallery’s version of Edouard Manet’s iconic painting Le Déjeuner sur l’Herbe is perplexing. It has long been thought to be a copy created after the iconic large-scale French masterpiece of the same title; a work described as a founding moment of modern art by the last great old master. The Courtauld’s smaller work, painted “in a curiously harsh and hasty style” (Wilson-Bareau, 1986), and the large Musee d’Orsay canvas has long been a subject of scholarly debate. The Courtauld canvas has indeed been considered to be a preparatory sketch, a later replica of the d’Orsay version, or even a copy by a later hand

This Courtauld “sketch” was purported to have been commissioned by a close friend of Manet, Commandant Hippolyte Lejosne. However, according to the Gallery archival records the Courtauld painting was understood to be a gift from the artist to his friend. Following the Commandant’s death, the Lejosne family (of Maison-Lafitte) approached the Galerie Duret, one of Manet’s key dealers in Paris, who took the work on commission. In June 1928, the small sketch was brought to the attention of Samuel Courtauld by his principal art advisor and top London art dealer, Percy Moore Turner. Mr. Courtauld purchased the painting, and later, in 1932, bequeathed it to the newly formed Courtauld Gallery

Although signed by Manet in the lower left, scholarly debate has also extended beyond the painting function and onto questions over attribution. Much has been written about the narrative and symbolic meaning behind the making Le Déjeuner sur l’Herbe but the ambiguous status of the Courtauld work is in no small part due to the fact that the painting had not the focus of a materials investigation, nor had it been painting treated in the Courtauld Conservation studio for over four decades. Now, after an in-depth material investigation and the full conservation treatment this paper endeavours to explore the relationship of the Courtuald’s painting to the largescale signature work housed in the collection of the Musee d’Orsay.

This paper is a typical collaborative story between art history, science and conservation. Working closely with the curator, the conservator and the conservation scientist considered the painting materials and artistic working practice in an attempt to shed new light on the meaning behind the making of Courtauld’s version of Manet’s iconic work. Using new techniques, such as macro-XRF scanning and steadfast archival research methods, it hopes to propose a possible chronology by looking at the notions of the artist’s sketches, working as well as later copies and finally look at the possibility of replicating by another hand.

Red-figure pottery is a type of ancient Greek ceramic that originated in Athens in the later 6th century B.C. It typically features decoration in diluted clay slip that turns black after firing and is painted on a clay body that appears reddish orange. This kind of ware was used in daily life, dedicated in sanctuaries, and placed in tombs. The “red” areas contain hematite (Fe2O3), and the black background contains magnetite (Fe3O4) and hercynite (FeAl2O4). The red and black designs of Attic pottery have been shown to result from a complex firing process involving cycles of oxidation, reduction, and reoxidation. Initially, fine-grained red hematite is reduced to a dense, vitrified layer of black magnetite and hercynite, which resists reoxidation. In the final oxidation step, only the coarse-grained, porous ceramic body reoxidizes to red hematite, creating a sharp contrast between the red figures and the glossy black background (1–3).  

The Harvard Art Museums house an impressive collection of Athenian red-figure pottery. This includes the focus of this study, the so-called Bouzyges krater (1960.345), a 5th century B.C. mixing bowl for wine and water, named after the protagonist of the mythological scene depicted on its front. Although there are areas of well-preserved red-figure decoration on the krater, other areas display various levels of discoloration. The pronounced differences between adjacent sherds suggest that some alterations occurred after the vessel was broken, likely due to its involvement in a cremation burial. In such burials, ceramic vessels, often used as grave goods, were likely thrown onto the pyre and then swept into the burial, leading to the discoloration seen on the krater. Funeral pyres can reach temperatures up to 1000 ⁰C, creating a partly reducing environment due to the evolution of carbon monoxide and dioxide from burning bodies (4). It is to be expected that the temperature and oxidation/reducing environment will vary across the pyre, causing the broken fragments to display different degrees of discoloration. On some fragments, the red ceramic is altered into grey due to the reduction of hematite. On others, the black gloss is partially altered into red, suggesting high-temperature oxidation of the iron oxides occurred in areas of the fire where oxygen was more abundant.  

The disassembly of this vessel as part of its conservation treatment provides an ideal opportunity to study the krater, shedding light on the high-temperature material changes observed from the surface of the slip to the bulk of the ceramic. Using techniques such as SEM-EDS, X-ray diffraction, Raman, and FTIR spectroscopy, this material study will be important for the conservation of similar ceremonial vessels, furthering our understanding of their involvement in ritualistic practices. 

References 

1. R. Jones, Adv. Archaeomaterials. 2, 67–127 (2021). 

2. M. Walton et al., J. Am. Ceram. Soc. 96, 2031–2035 (2013). 

3. S. Balachandran, Arts. 8, 70 (2019). 

4. M. S. Walton, M. Svoboda, A. Mehta, S. Webb, K. Trentelman, J. Archaeol. Sci. 37, 936–940 (2010).