|AIC members from all specialty groups are invited to attend and participate in the event “A failure shared is not a failure: learning from our mistakes,” happening on Saturday, June 2nd, from 4:30 to 6:00 p.m. — click here to add it to your Sched. We will gather and share our cautionary tales, including treatment errors, mishaps, and accidents, with the idea of helping our colleagues not to repeat them.
Discussing mistakes is a hot topic that has already been embraced by others in our community. Two examples of events scheduled during the month of May are: “Mistakes were made,” a regular feature at the American Alliance of Museums conference, and the lecture “Conservation Confidential” hosted by our conservation colleagues across the pond in the Independent Paper Conservators’ Group.
Participants can speak for up to 5 minutes; if you prefer to remain anonymous, a reader will be happy to present your tale on your behalf. If you are unable to attend AIC’s Annual Meeting but would like to submit a tale to be read by one of our organizers or a colleague, please reach out.
Screens to project PowerPoint slides containing your images/video will be available (16:9 format), and a Dropbox folder will be made available for submissions. Please also bring your presentation on a USB Drive (highly encouraged). Time permitting, audience members inspired by their colleagues will be welcome to present. If appropriate (and acceptable to the speaker), the floor will be opened for questions and discussion following presentations. Extra points for suggesting safeguards and solutions!
Please note that this is a forum for sharing personal mistakes and solutions only. Participants are requested not to name other persons, organizations, work places, and avoid politics—institutional, national, and global!
The event will include a cash bar, so come, relax, unwind, share, laugh, groan, and learn. We plan to publish the event for those who wish to be included.
If you are interested in participating or have questions about the event, please contact Tony Sigel at firstname.lastname@example.org or by calling 617-767-1900 (cell), or Rebecca Gridley at email@example.com by May 10th.
Please include 2-3 quick sentences introducing your topic and indicate whether you plan to use a PowerPoint with images and/or video.
See you in Houston!
This blog post is part of a series of observations about the London “Gels in Conservation” conference co-hosted by the Tate and IAP (International Academic Projects, Ltd). In mid-October, over the course of three days, some 41 authors presented research, techniques and ideas on gels in conservation. The talks were excellent, and I’ve focused on four that were notable for the wide range of materials treated and challenges faced. They ranged from coating/grime removal from a giant sequoia tree cross section, to dirt and varnish removal from Delacroix wall paintings, to removal of repairs from a fragile felt hat from a 18th century ship wreck, and an experiment comparing residues left behind by various gels on paper.
In the second of four talks, Alina Moskalik-Detalle presented “Conservation of murals by Eugene Delacroix at Saint Sulpice, Paris.” The talk was interesting for its scale and challenges. Because I’ve gone to see these murals many times over the years, the talk was also personally interesting. Each time I visited, I left somewhat disappointed by the darkened, flat, dull murals. As luck would have it, I was scheduled to travel to Paris a week after attending the gels conference. What I saw when I visited Ste. Sulpice was truly remarkable—color, depth, and drama. The cleaning had totally transformed these murals. Naturally, I couldn’t help myself, I actively looked for shiny patches—the results from this treatment were remarkable. This multi-year project involved numerous conservators including collaboration with Richard Wolbers. Some of the treatment challenges included flaking paint, complex paint layers, multiple restorations, rising damp in the walls, carbon based grime, and, if that wasn’t enough, the paint was very sensitive to organic solvents. The conservators wanted to limit penetration of their solvent gels without leaving a residue or tide line behind. They wanted good contact between the gels and the substrate, control of the action of water, and to create mixtures of solvents that would clean effectively without damaging the paint layers. After cleaning tests were performed, a treatment protocol emerged: by pre-saturation of the areas being treated with cyclomethicone followed by the application of silicone solvents gels to the mural’s surfaces, tide lines were avoided, grime could be removed, the gels could be cleared, and residue was limited. The D4 was a slow evaporator which allowed about a 30 minute working time for the application of the gel and subsequent grime removal without harming the paint layer.
The gels were made and applied in a paste-like consistency for maximum control of where the material was placed. It clung to the vertical walls and horizontal ceiling long enough to be effective. Using D4 based emulsions to clean the mural’s paint surfaces allowed the removal of surface soil without stripping wax or oily components from the paint films themselves. Because the emulsions were surfactant free, it was easier to clear them from the treated surfaces. Analysis of samples didn’t show residue left behind on the surface, but when the conservators tried to consolidate flaking areas of paint, they had trouble with adhesion, it is unclear why. It will be interesting to see how these murals age over time and if further treatment is needed in future, how re-treatable it is.
This blog series is a result of receiving the FAIC Carolyn Horton grant to help me attend the conference. I would like to gratefully acknowledge the FAIC for helping make it possible for me to attend this important conference.
From June 9th – 11th 2016, an interdisciplinary conference for conservators, curators, and art scholars was held in Kassel, Germany, organized by the paintings specialty group of the German Association of Conservators (Verband der Restauratoren VDR) and the Museum Landscape Hessen Kassel (Museumslandschaft Hessen Kassel). The conference’s topic “Layer by Layer – The significance and aesthetic of the surface” (Schicht um Schicht – Die Bedeutung und Aesthetik der Oberflaeche) aimed to give an extended view on various types of objects focusing on surfaces in all their facets and raised thought-provoking questions. What importance do we ascribe to the original surface when we look at an object? What impact do irreversible conservation treatments have on our aesthetical perception of an object? How do conservators, curators, artists, and visitors observe, describe and interpret surfaces?
On the one hand, observations and interpretations happen through visual and scientific examination, based on experience and analysis of conservators and scientists. On the other hand art historians analyze objects and their surfaces in their historical context. Perception psychologists who also participated noted that these kinds of different interpretations are not just a result of a profession or particular methods, but are also influenced by individual interests and especially individual perception.
The title of the conference already implied that the talks wouldn’t just scratch the surface, thus not just give a superficial overview of an objects surface, but rather go in depth. Presentations and following conversations discussed how various layers and sometimes damages within them affect the character of the surface – intended or not.
Furthermore, the variety of presented objects, speakers from different fields of conservation and speakers from other disciplines showed the broad range and importance of the topic: surface. The conference offered a platform for participating experts from various fields to discuss their experience and opinions. However, it also showed us that we will continue to struggle with defining and describing specific appearances, causes and effects as we face the limitations of our individual perceptions and terminology. Lastly, the conference highlighted the importance of continuing conversations across fields, where accurate and clear terminology can be incredibly beneficial. Ultimately, improved communication and understanding will benefit the object, its preservation and presentation, and is nevertheless essential for our decision making process.
As most of the conference was held in German, this English summary has been provided to encourage and support a transnational exchange of ideas and information. The following outline is based on the conference’s booklet with its short abstracts, notes taken by the author of this post and a German review written by Cornelia Peres and Dirk Welich. For more specific information please contact firstname.lastname@example.org.
- Anne Harmssen: About finiteness of immaculately beautiful surfaces
- Nathalie Baeschlin: Fragile and precious – tense painting surfaces of the 20th century
- Dr. Helmut Leder: Perception of art from an empirical aesthetic research point of view. Is it a question about style?
- Dietmar Wohl: Assertions about surfaces of paintings in the theories of conservation and restoration
- Dr. Martina Sitt: Still not close enough? Problems about exchange of knowledge between art history and conservation
- Sybille Schmitt: Systematic tools and resources to determine and evaluate surface and structure on baroque paintings
- Cornelius Palmbach: Active Thermography – visualization of damages and hidden structures in paint layers and other coated surfaces
- Theresa Braeunig: Crucifix – reconstruction and composition of a late Gothic work using 3D-technology
- Susanne Litty, Mira Dallige-Smith: Brilliant sh(r)ine – the complexity of original and alteration shown on a North Indian miniature-altar as an example
- Thomas Kraemer: Changes in a paintings surface through thinning or removing varnishes. An example from the Gemaeldegalerie Alte Meister in Kassel
- Joerg Klaas: “Like greyblue painted surfaces” – Alterations of ultramarine containing paint layers in easel paintings
- Linda Haselbach, Dr. Albrecht Pohlmann: Efflorescence, blanching, protrusions – Fatty acid dissociation and lead soap building in oil studies by Adolf Senff
- Andreas Krupa: Reconstruction as a conservation treatment? – Sheen and color of a furniture surface with mahogany-appearance
- Andreas Hoppmann: Varnish separation on a triptych by Bartholomaeus Bruyn the Elder
- Sabine Formanek: A surface that is polished with “chalk and water and a piece of felt till it appears like glass” restoration of a tabletop with a transfer decoration
- Jonathan Bikker: What’s so funny about impasto? Arnold Houbraken’s lampooning of Rembrandt’s use of texture in perspective; Talk given in English
- Stefanie Lorenz: Conservation of River scenery by Jacob Philipp Hackert, 1805. A method for a layer selective varnish removal
- Babett Forster, Romy Koenig-Weska: The portrait as a palimpsest. Layer by layer in scholar portraits from Jena
- Felix Muhle: Delicate sheen: Polished white bole in abbot Anselm II. “Wohncabinet” in cloister Salem, Southern Germany
- Eva Bader: Surface cleaning of the installation Barraque D’Dull Odde by Joseph Beuys at the Kaiser Wilhelm Museum in Krefeld, Germany
- Franziska Bolz: Shoe-paste, sand and fire – artificial aging as a part of Tingatinga-paintings from Tanzania (East Africa)
- Caroline von Courten: The Photographic Surface as Interface in mixed-media photo-works: Layers of materials, processes and meanings in Ger van Elk’s Dutch Grey, 1983/84
- Dr. Dietmar Ruebel: Handcraft and machine aesthetic – surfaces as internal memory of 20th and 21st century art
- Helena Ernst: The Keep by Mike Kelley at the Museum Brandhorst, Munich, Germany
The conference opened with an introduction given by Justus Lange, who demonstrated how different surfaces are perceived nowadays and how they have been perceived in the past. By discussing initial ontological issues of surfaces, he showed how relative and subjective the appraisal process of a surface can be and thus, prefaced the first session of the three-day long, interdisciplinary conference.
Anne Harmssen: Von der Endlichkeit makellos schoener Oberflaechen
Anne Harmssen: About finiteness of immaculately beautiful surfaces
Anne Harmssen presented in the first talk of the conference a three dimensional object by contemporary artist Carola Keitel called O 11 (Objekt 11). Her work perfectly represented the conference’s theme and showed how essential the material properties – and therefore surface and texture can be essential for an object’s meaning. Harmssen described Keitel’s meticulous method of treating the object’s metal surface, in which she has used a regular trashcan and transformed it to an artwork with an absolute pristine surface. Due to a damage on the object, Harmssen was confronted with the question whether or not and how to repair the damage in an immaculate surface. The artist herself saw the integrity of the piece compromised and hence the object itself destroyed. Harmssen, who is also owner of the object, decided not to follow the artist’s suggestion to grind the entire surface down, therefore recreating a pristine and perfect surface again, but rather decided to conduct a localized treatment. The talk was followed by a discussion as to whether the existence of this particular object is founded on its surface and can only be justified by its immaculate state and whether the object’s integrity and perfection is more important than its history.
Nathalie Baeschlin: Fragil und prezioes – spannungsvolle Gemaeldeoberflaechen des 20. Jahrhunderts
Nathalie Baeschlin: Fragile and precious – “tense” painting surfaces of the 20th century
Following Harmssen, Nathalie Baeschlin presented a paper based on several examples, such as paintings by Picabia and Mondrian and objects of raku ware, where either the fragility of the surface or the entire layer structure can be essential part of the artwork if intended by the artist. For example, she described how Picabia experimented with crackle lacquer and other methods to create intentional fissures through layering. However, her remarks about the surfaces of 20th century paintings and their intended fragility made clear that special properties of a surface can be intrinsic to the object, thus untouchable as an element of its meaning.
Prof. Dr. Helmut Leder: Wahrnehmung von Kunst aus der Sicht der empirischen Aesthetikforschung. Eine Frage des Stils?
Prof. Dr. Helmut Leder: Perception of art from an empirical aesthetic research point of view. Is it a question about style?
Unlike Baeschlin, Prof. Dr. Helmut Leder as well as Dietmar Wohl, focused on the unintentional changes in surfaces and discussed how viewers perceive them. Among other substantial aspects of perception, Leder presented a model of aesthetic processing, in which aesthetic experiences involve five stages: perception, explicit classification, implicit classification, cognitive mastering and evaluation. Leder presented results of perception studies regarding questions of an artist’s style: How long does it take to perceive style? Do we see style as the means of how the art object was created or produced?
Further reading: Leder et al.: A model of aesthetic appreciation and aesthetic judgments, in: British journal of Psychology Vol 95, Issue 4, 2004, pp. 489-508.
Dietmar Wohl: Aussagen in den Theorien der Konservierungs- und Restaurierungswissenschaft zur Oberflaeche von Gemaelden
Dietmar Wohl: Assertions about surfaces of paintings in the theories of conservation and restoration
Dietmar Wohl explained how an increasing “scientification” of conservation and restoration leads to various sub disciplines, each one with its own theories, e.g. practical conservation, conservation history and technical art history.
Prof. Dr. Martina Sitt: Noch nicht nah genug? Problem des Wissenstransfers zwischen Kunstgeschichte und Restaurierung
Prof. Dr. Martina Sitt: Still not close enough? Problems about exchange of knowledge between art history and conservation
Prof. Dr. Martina Sitt illustrated how contributions by conservators in museum and exhibition catalogs in recent years have enriched our knowledge about an artist’s oeuvre. However, incorporation of these contributions within the analysis of a work is often still insufficient. New information and knowledge gained through conservation treatment and examination are often presented as raw data, not communicated well enough and hence difficult to integrate accurately. This unfortunately results in a crux of two different specific terminologies used in two different fields attempting to discuss the same object. Based on paintings by Teniers, van Delen and Gruenewald, Dr. Sitt’s talk discussed possibilities and problems of exchange between the two fields in a very clear and enriching way.
Sybille Schmitt: Systematische Hilfsmittel zur Bestimmung und Bewertung von Oberflaeche und Struktur an barocken Gemaelden
Sybille Schmitt: Systematic tools and resources to determine and evaluate surface and structure on baroque paintings
As Sybille Schmitt could not present her talk in person, a colleague read her paper, which outlined the importance of an accurate terminology when it comes to describing layer structures, especially on a microscopic scale. By drawing an analogy to geomorphology and its terminology used to characterize variances in layer structure and surface, she introduced a helpful toolkit to conservators that both, describes and evaluates surface changes in paint layers. Despite huge differences in scale between microscopic cross sections of paint layers and the earth’s stratigraphy, the comparison of different phenomena created by physical, chemical or biological processes and forces was very persuasive to me. An example, which compared layer deformation caused by lead soap building to geomorphological deformation was fascinating and surprisingly accurate. It remains uncertain, if and when conservators will choose to adopt this toolkit or terminology.
Cornelius Palmbach: Aktive Thermografie – Visualisierung von Schaeden und verborgenen Strukturen an Malschichten und anderen Oberflaechen
Cornelius Palmbach: Active Thermography – visualization of damages and hidden structures in paint layers and other coated surfaces
Cornelius Palmbach gave an impressive overview of an Active Thermography project conducted at the Bern University of applied sciences BFH (Bern, Switzerland). Palmbach used Active Thermography as a non-destructive imaging technique to locate, visualize, and quantify both hidden structures and damages located beneath coated surfaces. Through subtle and periodical warming of an object’s surface, underlying areas that differ in their thermic properties give different responses that can be then detected with an IR-camera (Lock-In thermography). Palmbach presented convincing examples as he illustrated the identification of lifting paint layers, veneer, and plaster.
Theresa Braeunig, Joerg Maxin, Iris Winkelmeyer: Kruzifix! Rekonstruktion und Gestaltung eines spaetgotischen Werkes mittels 3D-Technik
Theresa Braeunig: Crucifix! Reconstruction and composition of a late Gothic work using 3D-technology
Theresa Braeunig discussed the examination of a nearly life-sized, late Gothic crucifix at the Lenbachhaus Munich, Germany. The project also involved the reconstruction and visualization of missing form elements and alterations in color design and the application of modern technology. 3D scanning and 3D printing helped visualizing the object’s appearance with different color designs from different time periods. Her work resulted in an exhibition dedicated to the research results and visualizations.
Further reading: Theresa Braeunig, Joerg Maxin, Iris Winkelmeyer: 3D-Rekonstruktion der Gestaltung eines spaetgotischen Kruzifixes aus Franz von Lenbachs Sammlung, in: Zeitschrift fuer Kunsttechnologie und Konservierung, Vol. 1, 2016, pp. 183-196.
Susanne Litty, Mira Dallige-Smith: Glaenzender Sch(r)ein – die Komplexitaet von Original und Ueberarbeitung am Beispiel eines nordindischen Miniaturaltars
Susanne Litty, Mira Dallige-Smith: Brilliant sh(r)ine -the complexity of original and alteration shown on a North Indian miniature-altar as an example
Susanne Litty described examination results of a miniature shrine in the collection of the Ethnologisches Museum, Berlin, Germany. The core theme to her talk was the difference between original and altered material, and related issues involving treatment-based decisions. The identification of a later application of a high gloss varnish, also known as “Soluble Nylon”, was one of the main challenges.
Thomas Kraemer: Veraenderungen der Bildoberflaeche bei der Duennung oder Abnahme von Firnissen. Ein Beispiel aus der Kasseler Gemaeldegalerie Alter Meister
Thomas Kraemer: Changes in a paintings surface through thinning or removing varnishes. An example from the Gemaeldegalerie Alte Meister in Kassel
Thomas Kraemer presented a treatment of the painting White Hen with Small Cake by Melchior de Hondecoeter, in the collection of the Gemaeldegalerie Alte Meister in Kassel, Germany. Kraemer’s talk focused on a highly solvent sensitive intermediate varnish layer that made the accurate removal and/or thinning of the top varnish layer with organic solvents impossible. Furthermore, the top varnish was discolored and had evolved a bark-like texture. Even though Kraemer had some success using a mastic resin-powder for mechanical varnish removal, he sought further improvement of the cleaning results.
Further reading: Thomas Kraemer: Veraenderungen der Bildoberflaeche bei der Duennung oder Abnahme von Firnissen. Ein Beispiel aus der Kasseler Gemaeldegalerie Alter Meister, in: VDR Beitraege zur Erhaltung von Kunst- und Kulturgut, Vol. 1, 2017, pp. 26-34.
Dr. Joerg Klaas, Dr. Heike Stege: “Wie graublau angestrichene Flaechen” – Die Veraenderungen ultramarinhaltiger Farbschichten in der Tafelmalerei
Dr. Joerg Klaas: “Like greyblue painted surfaces” – Alterations of ultramarine containing paint layers in easel paintings
Dr. Joerg Klaas’ presentation focused on “ultramarine sickness” in paintings. Klaas has worked on this degradation phenomenon for several years and published about it in his dissertation at the TU Munich in 2010/11. Within this project, his research covered the examination of paintings from 1475-1720. The examination of several paintings from this time period and mock-ups indicates that the “ultramarine sickness” is not a chemical discoloration, but rather a separation of pigment and binder that causes ultramarine containing layers to appear opaque and lighter or grey.
Further reading: Dissertation in German
Linda Haselbach, Dr. Albrecht Pohlmann: Ausbluehungen, Weissschleier, Protrusionen: Fettsaeureabspaltungen und Schwermetallseifen in den Oelstudien des deutsch-roemischen Malers Adolf Senff (1785-1863)
Linda Haselbach, Dr. Albrecht Pohlmann: Efflorescence, blanching, protrusions: Fatty acid dissociation and lead soap building in oil studies by Adolf Senff
Haselbach and Pohlmann showed a variety of botanical studies by Adolf Senff, most of them executed in oil on paper. 59 similar studies are in the collection Kunstmuseum Moritzburg in Halle (Saale), Germany. Several studies show varying amounts of degradation on the surface including efflorescence, blanching, and protrusions. Haselbach, who wrote her master’s thesis on this project, discussed possible causes for the types of degradation and suggested different treatment options, such as removal, inpainting, varnishing and preventive methods.
- Thesis in German
- Linda Haselbach, Dr. Albrecht Pohlmann: Ausbluehungen, Weissschleier, Protrusionen: Bildung von Schwermetallseifen in den Oelstudien des deutsch-roemischen Malers Adolf Senff (1785-1863), in: VDR Beitraege zur Erhaltung von Kunst- und Kulturgut, Vol. 1, 2017, pp. 7-18.
Andreas Krupa: Rekonstruktion als restauratorische Massnahme? – Glanz und Farbe einer Moebeloberflaeche mit Mahagoni-Optik
Andreas Krupa: Reconstruction as a conservation treatment? – Sheen and color of a furniture surface with mahogany-appearance
Andreas Krupa discussed the difficult conservation treatment of a Biedermeier escritoire (1840, Northern Germany). Cumulative light exposure resulted in a faded and matte appearance of the escritoire that contrasted with other examples of furniture from that time period. These examples were still in good condition and showed a rich, saturated, glossy and Mahogany-red surface. However, several attempts to re-saturate the surface of the escritoire either failed or lead to unsatisfying results. Poor results led Krupa to build a reconstruction following historical models and recipes, gaining unexpected experience and outcomes.
Publication in VDR Beitraege zur Erhaltung von Kunst- und Kulturgut pending.
Andreas Hoppmann: Firnistrennung an einem Triptychon von Bartholomaeus Bruyn der Aeltere – Ein wahrgenommener Gluecksfall
Andreas Hoppmann: Varnish separation on a triptych by Bartholomaeus Bruyn the Elder
Andreas Hoppmann presented one of those rear case studies where a selective varnish removal was conducted. On a Triptych by Bartolomaeus Bruyn (the Elder) a heavily discolored varnish was removed by using an alkaline buffer solution. Conservators were able to separate the top layer of oil-containing varnish from the resinous varnish underneath without damaging lower layers. The selective cleaning revealed a barely discolored resinous varnish layer that was in good condition.
Further reading: Andreas Hoppmann, Firnistrennung an einem Triptychon von Bartholomaeus Bruyn der Aeltere: Ein wahrgenommener Gluecksfall, in: VDR Beitraege zur Erhaltung von Kunst- und Kulturgut, Vol. 2, 2016, pp. 96-101.
Sabine Formanek: Eine Oberflaeche die mit “Kreide und Wasser und einem Stueck Filz solange geschliffen, bis es wie Glas ist” – Die Restaurierung einer Tischplatte mit Umdruckdekor
Sabine Formanek: A surface that is polished with “chalk and water and a piece of felt till it appears like glass” – restoration of a tabletop with a transfer decoration
Sabine Formanek showed her treatment of a table that was designed using an unusual transferware technique (1830, Museum fuer Angewandte Kunst, Vienna, Austria). Formanek described the transfer technique itself, damages and condition issues, and various treatment steps including consolidation, cleaning, filling, inpainting.
Dr. Jonathan Bikker: What’s so funny about impasto? Arnold Houbraken’s lampooning of Rembrandt’s use of texture in perspective; Talk given in English
Dr. Jonathan Bikker from the Rijksmuseum illustrated Rembrandt’s various ways of manipulating paint to create surface texture, such as his early use of the butt-end of his brush or a palette knife, which he used later in his career. Bikker also discussed how Arnold Houbraken, Dutch painter and writer in the Golden Age, criticized Rembrandt for this “rough” manner of painting, which contrasted with the fine and the loose manner exemplified by Frans Hals.
Stefanie Lorenz: Die Restaurierung des Gemaeldes “Flusslandschaft” von Jacob Philipp Hackert – Eine Methode zur schichtenselektiven Firnisabnahme
Stefanie Lorenz: Conservation of River scenery by Jacob Philipp Hackert, 1805 – A method for a layer selective varnish removal
Stefanie Lorenz presented the treatment of a painting by Jacob Philipp Hackert in the collection of the Alte Nationalgalerie, Berlin, Germany. Lorenz’s self-described greatest challenge of the treatment was the cleaning of the painting, which had a discolored and patchy surface appearance. Close examination revealed five different varnish layers in dark areas whereas bright areas, such as the sky, showed less layers, but also some intermingled ones. Furthermore, there was evidence for residues of an original varnish, which complicated varnish removal using free solvents. Based on this initial situation, Lorenz tested several treatment options for cleaning and presented an interesting and successful mechanical varnish removal using a melamine resin sponge.
Further reading: Stefanie Lorenz: Die Restaurierung des Gemaeldes Flusslandschaft von Jacob Philipp Hackert. Eine Methode zur schichtenselektiven Firnisabnahme, in: VDR Beitraege zur Erhaltung von Kunst- und Kulturgut, Vol. 1, 2017, pp. 19-25.
Dr. Babett Forster, Romy Koenig-Weska: Das Bildnis als Palimpsest – Schicht um Schicht in Jenaer Gelehrtenbildnissen
Dr. Babett Forster, Romy Koenig-Weska: The portrait as a palimpsest – Layer by layer in scholar portraits from Jena
Dr. Babett Forster and Romy Koenig-Weska showed a variety of portraits from the University in Jena, Germany. From 1548 to the late 18th century, many scholars donated their portraits, often equipped with inscriptions, to the university. Research by Foster and Koenig-Weska has shown, that many of these inscriptions were altered through the centuries. However, some of these covered and overwritten inscriptions start reappearing or are getting uncovered by conservators. The presentation emphasized a complex discussion concerning the preservation and presentation of those portraits in consideration of factors, such as legibility and importance of historic alterations and documents, aesthetics of the portrait, and possible treatment solutions.
Dr. Felix Muhle: Empfindlicher Glanz: Die Fassungen auf Porcellain-Arth im “Wohnkabinet” Abt Anselms II. In Kloster Salem
Dr. Felix Muhle: Delicate sheen: Polished white bole in abbot Anselm II. “Wohncabinet” in cloister Salem, Southern Germany
Felix Muhle discussed the “Wohncabinet” of Abbot Anselm II, at cloister Salem, Germany, focusing on the plaster and furniture elements, which were added by Johann Georg Dirr between 1763-1766. Muhle stated that furniture, sculptures and plaster frames were mostly preserved with their original polished white bole that is imitating porcelain. The presentation covered technical as well as aesthetic aspects of sheen and material imitation and discussed possibilities and limits of cleaning and reduction of grime on water sensitive surfaces.
Eva Bader: Die Oberflaechenreinigung der Installation “Barraque D’Dull Odde” von Joseph Beuys im Kaiser Wilhelm Museum Krefeld
Eva Bader: Surface cleaning of the installation Barraque D’Dull Odde by Joseph Beuys at the Kaiser Wilhelm Museum in Krefeld, Germany
In 1977 Joseph Beuys himself installed Barraque D’Dull Odde at the Kaiser Wilhelm Museum in Krefeld, Germany. The work consists of 650 individual pieces embracing felt, food, dead bees, piles of loose chalk, a dust painting and many other curiosities. This installation represents one of the last “untouched” pieces by Beuys. The preservation of the original installation as well as the great variety of materials complicated the removal of dust that accumulated in almost 40 years. Eva Bader brillantly discussed not just Beuys work process, intentions and created effects, but also presented several conservation approaches for surface cleaning such a complex installation as well as suggested options regarding preventive conservation.
Franziska Bolz: Von Schuhcreme, Sand und Feuer – Kuenstliche Alterung als Bestandteil von Tingatinga-Gemaelden aus Tansania (Ostafrika)
Franzska Bolz: Shoe-paste, sand and fire – artificial aging as a part of Tingatinga-paintings from Tanzania (East Africa)
Franziska Bolz presented her extensive research on Tingatinga style paintings, named after the creator Edward Saidi Tingatinga, who painted in Tanzania at the end of the 1960s. Before he died in 1972, he taught his technique to friends and family members, many of who continued to make Tingatinga-paintings. The paintings are known for their high gloss lacquer paint, which is sometimes patinated with dust, shoe-paste and/or soot. Bolz discussed the intention, genesis, history and integrity of the paintings made by the artist himself compared to today’s practicing artists. She also addressed issues of authenticity and forgery.
Caroline von Courten: The Photographic Surface as Interface in mixed-media photo-works: Layers of materials, processes and meanings in Ger van Elk’s Dutch Grey, 1983/84
Unfortunately Caroline von Courten’s presentation on Ger van Elk’s painted silver-gelatin print Dutch Grey (1983-84) had to be canceled. However, in the abstract she discusses signs of the print’s early degradation. The painted surface of the print has changed due to the unintended migration of silver particles. Based on this case study, von Courten shows, “how the changing photographic surface becomes the visible juncture between what is usually separated as immaterial image and physical image carrier”. (Quote from Caroline von Courten’s abstract in conference booklet)
Caroline von Courten: The Photographic Surface as Interface in mixed-media photo-works – Layers of materials, processes and meanings in Ger van Elk’s Dutch Grey, 1983/84
Prof. Dr. Dietmar Ruebel: Handarbeit und Maschinenaesthektik – Oberflaechen als Arbeitsspeicher in der Kunst des 20. und 21. Jahrhunderts
Prof. Dr. Dietmar Ruebel: Handcraft and machine aesthetic – surfaces as internal memory of 20th and 21st century art
In Prof. Dr. Dietmar Ruebel’s absence, a colleague read his talk about handcraft and machine aesthetic – surface as internal memory of 20th and 21st century art, to the audience. In his paper he illustrated tool marks found on surfaces of mainly three-dimensional objects.
Further reading: Dietmar Ruebel, Handarbeit und Maschinenaesthektik. Oberflaechen als Arbeitsspeicher in der Kunst des 20. und 21. Jahrhunderts, in: VDR Beitraege zur Erhaltung von Kunst- und Kulturgut, Vol. 2, 2016, pp. 88-95.
Helena Ernst: “The Keep” von Mike Kelley im Museum Brandhorst
Helena Ernst: The Keep by Mike Kelley at the Museum Brandhorst, Munich, Germany
Helena Ernst presented her research and treatment on Mike Kelley’s The Keep, now in the collection of the Museum Brandhorst. Kelley’s use of various materials and especially their condition when he completed a piece requires new conservation approaches to preserve both the intention and appearance of the object. Based on the battered door of this installation, Ernst explained what condition issues she had to deal with prior to the treatment. The issue of flaking and lifting paint on the battered door was even more complicated as Kelley intended and expected visitors to come close to the door, even touch it and look through a fish eye to experience the installation. In her talk Ernst also showed how the appearance of the door was probably more important than the door itself and how even material losses are intentional. However, conservators and curators discussed how much loss is acceptable and how much loss is preventable, to support the artist’s intention. Ernst described various consolidation methods, such as insertion of pieces of coated Japanese paper that functioned as a hinge for flaking paint. This method enabled the consolidation of flaking paint without loosing the character of a battered and flaky surface.
Further reading: Helena Ernst: The Keep von Mike Kelley im Museum Brandhorst. Die Sicherung der Farbschicht: eine konservatorische Herausforderung, VDR Beitraege zur Erhaltung von Kunst- und Kulturgut, Vol. 1, 2017, pp. 35-44.
Presenting on Thursday, Suzanne Siano, Chief Conservator and Director of Modern Art Conservation in New York, set about to detail the some of her history of artist-conservator collaborations. Initially Suzanne set the stage by providing examples of the theme “Collaboration to Restore”, with artists Glenn Ligon and Louise Fishman. The focus however was on the epic collaboration with artist Dan Colen.
Dan Colen led a wild lifestyle that in recent years has mellowed to include living on a farm and painting for a children’s hospital. This bucolic turn, however, is not reflected in the materials and techniques he and his idiosyncratic studio assistants employ in his artistic practice, of which he retains ownership of the final artistic product. His list of materials are a cacophony of items: oil paint, flowers, crack pipes, concrete, living birds (parakeets), Styrofoam and most relevant to this talk, chewing gum. These lush, colorful assemblages ranged in size from quite small to over 17 feet long. The multi-colored creations had gum in all shapes and forms, glommed onto a support. In one example, the humidity drove up too high, resulting in the activation of the sugars of the gum. The result? Drips formed and delamination of some of the gum pieces occurred. Suzanne’s treatment, in concert with the artist’s wishes, focused on re-adhering of the delaminated gum pieces and removal of the drips. No filling, no inpainting, no stain reduction as per the artist’s request. Though Suzanne suggested that the artist construct a gum that was sugar-free, the artist insisted that the degradation was part of the artwork. Colen did adopt her suggestion of pre-primed canvas and rigid panels.
But let’s back up a few years to when Suzanne met Dan. Well actually Dan’s assistants, because Suzanne and Dan didn’t formally meet at the onset of the first project in 2013. That project involved feathers coated in two types of tar; one was solvent based which was fine and the other was water-based, which had mould growth. The artist needed a support that allowed air-flow that would reduce the chance of future mould growth and Suzanne worked with them to create better stretchers.
Throughout the presentation, Suzanne engaged the audience with the overarching theme of the exploration of the artist’s working method and the integration of the conservator. One statement that resonated with me: as conservators, we collaborate while trying to stay ethical. To me, this relationship can be fraught with difficulty, as we try to steer the artist away from their sometimes-problematic choices. It’s like watching your partner’s new fiancé boil an egg for eighteen minutes: you want to tell them this is not going to end well (because you have the knowledge), but you don’t have the honest relationship yet that allows you to make any comment whatsoever (because there are boundaries). This is not what we anticipated when we were training as conservators, insofar as we were taught to focus on the object. The artist was the distant (read: likely long deceased) element and we had a responsibility to execute best practice for the preservation of the artwork. Suzanne reminds us that our role has evolved, and that with an effective artist-conservator relationship the artist is free to be courageous and bold. Now, the conservator is less constrained in our role, as the artist sees us a new resource. If we think back to some of our most challenging projects, we lament the fact that conservators didn’t get a chance to help inform the artist of the fallibilities of their methods or materials. Moving forward, Suzanne gives us a framework for fostering a respectful and informed relationship with artists, reminding us that our role is an evolution and with that evolution, we can ourselves be enriched.
Not often does one read about the use of reptiles in art conservation. Interest immediately spikes with the word gecko, that warm climate lizard that you often cross paths with during your much-needed tropical vacation.
In our efforts to find novel and non-destructive methods to clean artwork, conservators and conservation researchers set about to find applications in corollary fields that might be adapted to our needs. During this PSG presentation on the Tuesday, Cynthia Schwarz presented the work being conducted alongside fellow contributors Hadi Izadi and Kyle Vanderlick, Cynthia stressed from the outset that this was a very early pilot study, but the depth of information would suggest that quite a bit of work has already been initiated. This work focused on the generation of a new cleaning tool that mimicked the unusual adhesion principles found in the tiny (no, really tiny) toe pads of geckos. This cleaning tool is called a μ-Duster, which is composed of PDMS (polydimethyl siloxane) fibrillary microstructures that are able to remove particulates from vulnerable surfaces.
Geckos have the ability to climb, adhere and release from just about any surface, and can remarkably unclog dirt that lodges in the toe pad structure simply by taking a few more steps atop your beachside resort table lamp. The primary mechanism for adhesion are van der Waals forces, which Izadi modified in the application to create a gecko-mimicking material. Like gecko pads, the goal was to create a dry technology that left no residues, left no mechanical damage and only required minimal force to use. The necessity of such a cleaning tool is high: conservators are confronted more and more with surfaces that are sensitive to liquids (aqueous and solvent-based), complex in nature (such as acrylic paint) and cannot tolerate the presence of any residues in the short or long term (absorbent surfaces). Gecko-inspired adhesive tapes are in use, so why not an adaptation as a cleaning tool?
In the testing, the micro-pillar cleaning tool touches the test surface in a dab and pinch method. Test surfaces were made to mimic an acrylic paint surface, which was composed of poly(methyl methacrylate) (PMMA) as well as actual artificially soiled acrylic paint films. Note that the soiling agents were a variety of silica spheres and that the team tested three different pillar sizes. Colorimetry, gloss measurements and SEM imaging monitored the test surfaces before and after testing. Tested alongside the μ-Dusters were other dry methods such as goat hair brushing and polyurethane cosmetic sponges. The results suggest that the μ-Dusters are able to not only remove loosely bound contaminants, but also sub-micrometric particles that were not removed by other methods such as traditional dusting methods. Concurrently it was revealed that the damage to the surface from the process was noticeable with cosmetic sponge and brush-dusting evidenced in lateral marks seen via SEM imaging, while the much gentler μ-Duster cleaned areas avoided said damage.
This initial foray into μ-Duster cleaning of vulnerable surfaces is very promising, and the researchers note that many factors will come into play during development. The challenges presented by this method include a learning curve (it isn’t a very intuitive method … one has to practice the technique), the roughness of the surface (with some resolution by creating a thinner backing for the μ-Dusters), the slowness of the activity, the repeated contact with the surface and the necessity of cleaning the μ-Dusters (possible need for solvents in the cleaning and re-use of the μ-Dusters). Future research includes methodologies that necessitate cleaning with progressively smaller sizes of pillars (analogous to sanding wood with finer grades of sandpaper), development of different tip shapes for a wider range of dust particle sizes, creating a roller/brayer type tool (which may not be ideal for paintings) and micro-structuring solid gels for cleaning. Cynthia revealed an exciting prospect in nanometric particle removal … this might include soiling agents such as tobacco smoke (goodbye wet cleaning) and an application of removing particles out of air bubbles trapped in the matrix of acrylic paintings.
Thanks to Cynthia and her colleagues for crafting a presentation that was derived from a topic replete with many physics and chemistry based components. I endeavored to draft this blog as an attendee that hails from the bench, and any errors in my interpretation are completely my own. I very much look forward to the growth of this new non-destructive cleaning model.
In her talk on ionic fixatives, Soyeon Choi, head conservator of works on paper at Yale Center for British Art, presented an overview of the history of ionic fixatives, an explanation of how they work, and the results of several experiments. I had been looking forward to hearing Soyeon’s talk, due to the potential usefulness of ionic fixatives for library and archives materials. As Soyeon emphasized throughout her presentation, this type of fixative is likely to be most useful in cases where saving the information is a higher priority over aesthetic appearance, such as in the case of modern and contemporary inks, which are sensitive to a wide range of solvents. Soyeon’s experiments focused on a wide range of inks and included a variety of tests with numerous ionic fixatives and several different contemporary inks.
Prior to this talk, I hadn’t realized that ionic fixatives had remained more popular in Europe than in the United States since they were introduced as a treatment technique in Germany in the 1980s. As Soyeon explained, ionic fixatives have been used for mass scale treatment in Germany since 1996, but simply have not caught on in the US, for a number of reasons. One of the main challenges in translating this technique into practice is that these fixatives are industrial products which are used in processing textiles, and are not commercially available on a small scale. A related challenge is that the names of the fixatives are proprietary, and therefore vary from country to country, so fixatives used for research and testing in Europe are either not available in the US or go by different names. And, as with all things industrial, the exact composition of these fixatives is proprietary and subject to change. Soyeon felt it would be useful to complete a study of ionic fixatives in the US, and having seen her talk, I agree!
Soyeon gave a brief and thorough description of the main categories of ionic fixatives, which can be either cationic or anionic, and explained how these differ chemically. Interestingly, it has been found that cationic and anionic fixatives work best when used in tandem rather than when used separately. She also explained that the main drawback of all ionic fixatives is that some permanent change in the color of the ink should be expected, and that these are most useful in situations where preserving legibility is the main goal. Her research focused on dye-based inks, and compared 13 different fixatives. The experiments included examining the effects of applying the fixatives, and then testing the efficacy of the fixatives using localized treatment.
The goal of the first experiment was to determine if the fixatives leave any residue in the paper after washing, and to see if it made any difference to wash before or after the fixatives dried. Whatman filter paper was used, and the fixatives were applied to the paper on their own, as in not over any ink. Samples were left either unwashed, washed before the fixative dried, or washed after the fixatives dried. The fixatives tested included Polymin, Lupamin, Cartafix FF, Cartafix SWE, Cartafix WA, Cartafix WE, Cassofix FRN, Catiofast 159(A), Catiofast 2345, Mesitol NBS/Rewin EL, Nylofixan HF, Catiofast 269, and Appretan. The samples were washed for 15 minutes, and were examined for fluorescing residue and compared under UV light. There was a range of results in terms of fluorescence, and the fixatives which showed little to no fluorescence were chosen for further experiments.
In the next experiment, the effect of accelerating aging on the washed samples was examined. In this experiment, unwashed and washed oven-aged samples were compared. The oven-aged samples were aged at 70oC, 50% RH for 96 days. The fixatives used were Catiofast 159(A), Cartafix FF, Cartafix WA, Cartafix WE, Catiofast 269, Lupamin 9095, Catiofast 2345, Nylofixan HF, and Mesitol + Rewin. The samples were examined in visible and UV light. One fixative, Nylofixan HF, stained the paper even without aging. The not washed oven-aged samples developed significant amounts of fluorescence, but the washed, oven-aged samples did not, which suggests that washing did a good job of removing the fixative.
Based on these initial test results, three fixatives stood out as the most viable, including Cartafix WE, Mesitol & Rewin, and Cartafix FF. These three fixatives were then tested with contemporary inks. The inks tested, included Winsor & Newton Calligraphy Ink, Bombay India Ink, and Higgins ink. The fixatives were applied over fixed and unfixed inscriptions, again on Whatman filter paper. The fixatives were mixed with methyl cellulose and applied on a suction platen to both the front and back of the samples prior to washing. Both fixed and unfixed samples were washed. As expected, the unfixed samples bled profusely. Most of the fixatives gave acceptable results, and some fixatives worked better with certain inks. Higgins ink did not do well with any of the fixatives.
As Soyeon summarized, there are many factors to consider when using ionic fixatives, and their use requires a lot of fine tuning. The fixatives permanently alter the media to some degree in terms of hue and saturation, and rinsing is important for long term stability. The fixative names change fairly frequently. Future tests may include the use of ionic fixatives with blotter washing vs. immersion washing, gel vs. solution application, and air drying vs. quick drying. Overall, I thought the experiments were helpful and thorough. There was a lot more information presented than I was able to capture, so I hope that Soyeon publishes this work someday.
In her talk “Treatment 305: A Love Story,” Kathy Lechuga, book conservator at the Indiana Historical Society, described a deep relationship with a treatment technique that was years in the making. Kathy punctuated her talk with references to Prince lyrics, which she used to emphasis her love for the versatility of her new favorite treatment technique. Treatment 305 was originally developed at Princeton and was presented by Brian J. Baird and Mick Letourneaux in 1994. It is described in the Book and Paper Group Annual, in an article which may be found here.
The talk began with a summary of why Kathy has found this technique useful, what sort of books this treatment is typically used for, and how it relates to the Indiana Historical Society mission statement. Typically, she has found it useful for printed books from the late 18th to 19th century, which fit into the “medium rare” category. As this category of book treatment isn’t often addressed, I enjoyed hearing two talks related to medium rare books, including Quinn Ferris’ talk, “Medium Rare: An innovative approach to the space between special and general collections.” As Kathy described, the books in this category within her institution included collections that are used frequently for research and exhibits, and the ultimate goal of treatment was to improve mobility and durability while maintaining an aesthetic appearance that was harmonious with the books’ time periods.
Kathy was inspired by the Treatment 305 technique, because it helped in many ways to meet her desired treatment goals. She found this technique appropriate for books with a weak binding and a strong text block, and found that it would allow her to create a tight back structure while minimizing the inherent weakness of the historic structure. However, she did decide to experiment with deviations from the exact Treatment 305 technique as described in the original 1994 article, in order to better accommodate the needs of specific volumes, and to incorporate more contemporary treatment practices.
The majority of the talk centered around four case studies which incorporated slight variations on the Treatment 305 technique. The books included in the case studies were similar in that all were missing significant portions of their original binding components, such as their spines, one board, or both boards, and dated to the late 18th century or 19th century. The treatment was varied slightly in each case study, in order to accommodate the needs of each particular volume. All four case studies varied slightly, although common features included minimal spine linings and new boards constructed from two pieces of 4-ply board which had been laminated together.
One component of one case study which really caught everyone’s attention, and resulted in a few audience questions, was Kathy’s use of a screen-printing kit to replicate the title information on the spine of a book. I also thought this was a great new tool to consider, because replicating an original spine is called for on occasion, and using new materials to replicate an aged aesthetic can be a challenge.
Covering a pair of practical case studies, Claire Winfield’s presentation on her recent uses of Butvar® B-98 was clear and informative. Winfield, the Associate Painting Conservator at Saint Louis Art Museum (SLAM), featured two artworks that share the characteristic of having friable matte paint, but the process and purpose for consolidation of each one varied. Her ability to modify her approach for each situation was guided by research and first-hand tests with Butvar® B-98.
Butvar® B-98 is one of a series of trademarked polyvinyl butyral resins, which are valued for their clarity, adhesion to varied surfaces, rheology, toughness, flexibility, and aging characteristics. Butvars® are available in a range of molecular weights (MW) and can be applied in a variety of solvents by brush or spray. They are typically used in objects conservation for materials such as deteriorated wood, stone, plaster, bone, fossils, and baskets, because they can retain a matte surface and cause little color saturation.
In both of Winfield’s featured treatments, she needed to stabilize paint without altering its optical properties – a steep challenge given their powdery surfaces. Winfield focused on the energy relationships between Butvar® B-98 and the painted surfaces, reducing the adhesive’s particle size (B-98 is the lowest MW Butvar® available) and spray applying it in multiple dilute coatings to promote penetration. Keeping the spray tip completely clean and pre-wetting the surface with solvent were helpful in this process.
The first case study was Enforcer (1962) by Larry Poons, composed of Liquitex acrylic paint and Fabspray on canvas. The Fabspray, a spray paint for fabric with vinyl and alkyd resin binders, unfortunately aged very poorly, having deteriorated to the point of actively shedding pigment. The goal of treatment was to keep the paint in place for safe dusting of the surface. Adhesive tests included Butvars® of varying weight, gelatin, and methylcellulose. Due to its small particle size, low viscosity in ethanol, strength, and minimal visual effect, a 1% Butvar® B-98 in ethanol was chosen as the consolidant. Since the Liquitex and Fabspray were applied to the painting in discrete areas, it was possible to mask the Liquitex areas while spray applying six coats of dilute consolidant to the Fabspray. The results were successful in that the paint no longer actively sheds and remains visually matte; however, the surface still cannot be safely dusted, and there was a slight but acceptable saturation of the color.
Micenic (c. 1942) by Siegfried Reinhardt, an oil painting on pressed board, was the second case study. The paint layer was locally cracked and lifting away from the board, and it was also lacking in cohesive strength: the lifting paint crumbled from brush contact and could not withstand heat. Following tests, the surface was pre-wet with 60:40 toluene:ethanol then then sprayed overall with 2% Butvar® B-98 in the same solvent mix to give the paint cohesive strength. Ethanol helped lower the viscosity of the adhesive, and toluene prevented tidelines caused by the paint’s slight ethanol sensitivity. BEVA® 371 in naphtha with heat assistance could then be applied to readhere the lifting paint to the board without undermining the cohesion provided by the B-98. This two-layer consolidation process successfully preserved both the structure and appearance of this painting.
Winfield’s work provided two responsible and creative examples for how Butvar® B-98 can be a useful addition to a paintings conservator’s toolkit.
On the final day of specialty group presentations at AIC’s Chicago meeting, Tiarna Doherty, Chief of Conservation at the Lunder Conservation Center, Smithsonian American Art Museum (SAAM), rewarded attendees with a lovely presentation about the singular artist Romaine Brooks. The Smithsonian Renwick Gallery mounted the exhibition “The Art of Romaine Brooks” in 2016, and Doherty examined over 30 paintings by Brooks in preparation, many of which were featured in the show. Weaving into a captivating story Brooks’s biography, aesthetic preferences, and technical practices, Doherty also conveyed the rationale for her practical conservation approach in response to how the paintings have altered over time.
Romaine Brooks (1874-1970) is known for her stunning portraits, often featuring friends who were leading figures in the arts and humanities at the time. Born in Italy but raised in New York, Brooks’s father left when she was young, and her mother was not supportive of Brooks’s artistic pursuits. From 1890-1900, she lived in Capri with many other ex-patriots with non-traditional lifestyles; the location was a refuge following Oscar Wilde’s 1895 trials in London. Brooks met her husband in Capri, but their marriage was unsuccessful in no small part because he disapproved of her preference for masculine attire. She eventually settled in Paris in 1905. Her unpublished autobiography, which she illustrated with drawings, was titled “No Pleasant Memories.”
Brooks recorded very little about her aesthetic preferences or artistic technique, leaving only her artistic output and a few historic photographs to fill in the blanks. Her painting technique reveals some academic knowledge, though she may not have had formal training. Chalk lines and colored ground layers, such as the salmon orange preparatory layer in The Charwoman (1904), were followed by thin washes of paint and numerous glazes composed of her own mixture of oil and resin. She often used oil paint to reinforce contours on top of natural resin varnish layers to create the final surface. Painted black dashes, and in one case silver dashes, define the outer boundaries of many paintings.
In addition to painting and drawing, Brooks demonstrated an innovative attentiveness to interior design. Frame design and surface finish were clearly a consideration in her pursuit of Whistler-influenced harmony of color and tone. In one example from Doherty’s presentation, Brooks had a particular frame with a large rabbet in mind when planning a painting’s composition, as she painted the canvas only where it would show within the frame window. In another example, both the painting and the frame had a black ground layer visible beneath the finished surface – such efforts earned the accolades of “reigning in harmony” in a 1910 exhibition review.
Not surprisingly, the natural resin-containing layers of Brooks’s paintings have darkened over time. Brooks herself may even have seen the changes begin, as she chose to keep most of her paintings until her death. The presence of glazes and varnish in alternating layers with original oil paint make conservation especially challenging. In addition, conservators at SAAM observed that later applications of Paraloid® B-72, now getting cloudy, were difficult to remove safely due to sensitivity of the original materials beneath. Treatment goals leading up to the Smithsonian’s exhibition were therefore a combination minimal intervention and passive technology. When possible, degraded varnishes were reduced and surfaces resaturated. To restore some of the original cooler tonality, gallery lighting was employed to virtually compensate for some of the current altered appearance.
Doherty reminded us of Oscar Wilde’s relevant words from The Portrait of Dorian Gray, that “some things are more precious because they don’t last long.” But a conservator does what she can. This careful study of an artist and her technique led to both a thoughtful approach for displaying Brooks’s paintings, aged but still striking; as well as this transmission of her harmonious original vision.
Claire’s talk highlights a topic that I’m glad we conservators are beginning to talk about more openly – treatments that didn’t necessarily work. This subject also fit in nicely with the overall conference theme of treatment and innovation. Although some of her treatment steps did not bring about the desired results, Claire was successful in safely and aesthetically preparing the ceramic so that it can be exhibited at the Freer Gallery of Art.
The earthenware dish features a reddish-buff ceramic body, off-white slip, and transparent glaze, with minimal brownish-black and red inscription decorations. The ceramic was previously broken into about 40 pieces and restored, with multiple campaigns of adhesive and overpaint. The museum has records of one treatment in 1964, and while removing old repairs, Claire found evidence of at least two previous restorations which likely occurred before the object was acquired in 1954. The major condition issue was various types to staining, including general yellow and gray stains. Additional disfiguring stain lines were present a few millimeters in from the edges of the sherds, including some areas with two or three separate rows of parallel staining.
Claire carried out analysis in an effort to determine the cause of the staining. Using SEM-EDS, among other tools, she determined that the staining contained little iron and was primarily organic in nature, meaning it is likely not from burial but from the various restoration campaigns. Adhesive identification was inconclusive, likely because multiple types are present; however, Claire noted the presence of hide glue, some type of acetone-soluble adhesive, and possibly shellac. During testing, the staining did not appear to be soluble in a range of solvents, likely because of crosslinking. Soluble salts were also identified with a microchemical test for chlorides, although no salt efflorescence was visible. An iron-containing accretion on the back within the footring was likely from burial and was mechanically reduced to avoid transfer to other areas of the ceramic during stain reduction treatment.
Claire proceeded with stain reduction tests, following Bruno Pouliot, Lauren Fair, and Richard Wolbers’ method of three rounds of poulticing using a chelator, bleach, and a final rinse.* She ultimately chose sodium citrate (2% at pH 8) as the chelator because it was mild yet effective, and she used carbamide peroxide (20% at pH 8) as the bleach. For both of these steps, she used agarose gel (2%) as the poultice material, favoring its ability for controlled, localized application. The gel poultices were only applied to stained areas on the front surface of the ceramic.
Agarose gel is made by mixing the powder with water, heating to a low temperature, pouring the mixture out to cast, and then cutting into blocks when cool. The gel blocks can then be soaked in solution; for instance, Claire soaked blocks in the chelator for one hour before applying to the ceramic. Plastic wrap was used to cover the gel blocks while on the ceramic to reduce evaporation. For the final rinse, the sherds were soaked in baths of deionized water, which served to clear the chelator and bleach as well as desalinate the ceramic.
To complete the treatment, the sherds were joined using Paraloid B-72, which was also bulked with microballoons and fumed silica to fill gaps and losses. These areas were inpainted as the dish will be displayed in an art museum, as opposed to an archaeological context, and the curator preferred to have the losses integrated.
Although the staining was somewhat lightened, its appearance was not sufficiently reduced by the poulticing steps. Claire carried out many poulticing trials, but the staining proved tenacious and she did not want to take the treatment so far as to risk causing damage to the object. Although improvements were made, the curator still did not find the dish to be in exhibitable condition, since the staining lines were still visible and particularly distracting against the overall stark, white appearance of the ceramic. At this point, Claire decided to try painting out the stains, over a barrier layer of B-72. Although she did not like the idea of painting over the original ceramic surface, this seemed to be the only reasonable option for preparing the object to be exhibited and accessible to public. Painting light over dark and matching the surrounding off-white glazed slip must have been a challenging task. But in the end, conservators and curators were both pleased with the results!
* For more information, I recommend: Bruno Pouliot, Lauren Fair, and Richard Wolbers. “Re-thinking the Approach: Techniques Explored at Winterthur for the Stain Reduction of Ceramics,” 2013 in Recent Advances in Glass, Stained-Glass, and Ceramics Conservation, pre-prints of the ICOM-CC Glass and Ceramics Working Group Interim Meeting and the Forum of the International Scientific Committee for the Conservation of Stained Glass, Amsterdam. pg. 211–223.