Conference posters by Cathy Silverman
A poster summarising my MA thesis, presented at 'Nanotechnology for Conservation' held at the Pra... more A poster summarising my MA thesis, presented at 'Nanotechnology for Conservation' held at the Pratt Institute in Brooklyn, January 2017.
A poster presented at European Lacquer in Context Conference held in Brussels, January 2018
Inherently fragile, japanned surfaces are often in poor condition and heavily restored. This can ... more Inherently fragile, japanned surfaces are often in poor condition and heavily restored. This can obscure the intention of the craftsman and confuse both stylistic and technical analysis. This paper will explore the usefulness of scanning X-ray fluorescence (XRF) - a non-invasive technique commonly used to visualize pigment distribution in historical paintings – for the investigation of japanned surfaces.
Areas of two eighteenth century American japanned chests in the collection of the Metropolitan Museum of Art were scanned using a Bruker M6 Jetstream system. Data was processed to produce elemental distribution maps. A set of samples reproducing the typical stratigraphy of eighteenth century japanned surfaces was also scanned in order to further probe certain unexpected results.
The ability to overlay elemental maps made it possible to quickly see where elements were occurring separately and together, aiding the idenification of pigments and other inorganic material. Processing the data quanititavely made it possible to differentiate between areas where the same elements appear in different ratios, which was often helpful in distinguishing between original and restoration materials. The maps also made it easier to locate areas where only a small amount of original material remained. In one case, a siginificant part of the decorative scheme hidden beneath overpaint was revealed.
The limitations inherent to the technique will also be discussed. XRF does not provide information about organic materials or layer structure. The equipment is expensive and significant time and expertise is required both to scan and to process the data. Additionally, the technique is currently only suitable for two dimensional surfaces. Although it was possible to scan areas with raised decoration, the depth of field and spot size had to be increased, resulting in a less focused image.
The scanning XRF technique was found to be a significant improvement on conventional point XRF for the technical understanding of complicated, heavily restored japanned surfaces. The technique allowed the plausible attribution of pigments, metals and other inorganic material to regions, with areas of inconsistency often being immediately evident from the elemental maps.
MA Thesis by Cathy Silverman
This study explores the suitability of ParaloidTM B-72 (B-72) modified with zinc oxide (ZnO) nano... more This study explores the suitability of ParaloidTM B-72 (B-72) modified with zinc oxide (ZnO) nanoparticles as an ultraviolet (UV) shielding coating for the conservation of historic clear coated wooden furniture. Coatings were tested for their ability to shield an underlying surface from UV radiation, whilst maintaining visible transparency.
The influence of the addition of different sizes and concentrations of powdered and manufacturer-dispersed ZnO nanoparticles to B-72 on the optical properties of resulting films was quantified using UV-Vis spectroscopy. A visual ranking of the transparency of the coatings was also made. The most promising coatings were then compared to B-72 with and without the typical organic UV absorber, oxybenzone. Coatings were applied to glass, placed over coloured printer inks on paper and exposed for varying durations to high intensity UV-A radiation. Any colour change of the inks was measured with a colorimeter, and used as an indicator of the UV- shielding capability of the coatings over time.
The results are encouraging, with the optimum coating increasing the UV-shielding by approximately 40% compared to unmodified B-72, with acceptable loss of transmittance in the visible range. However, further research would be required before recommending any treatment based on these coatings.
Articles by Cathy Silverman
Papers presented during the General and Concurrent Sessions, AIC’s 51st Annual Meeting, Vol. 2, 2023
The exhibition Bámigbóyè: A Master Sculptor of the Yorùbá Tradition, at the Yale University Art G... more The exhibition Bámigbóyè: A Master Sculptor of the Yorùbá Tradition, at the Yale University Art Gallery (YUAG), reunited more than thirty woodcarvings attributed to the workshop of Nigerian sculptor Moshood Olusomo Bámigbóyè (ca. 1885–1975). Carved in most cases from a single block of wood, and sometimes decorated with pigment, these objects are highly susceptible to changes in relative humidity (RH), with large fluctuations risking catastrophic failure. Wooden objects loaned by the National Museum, Lagos, Nigeria, a museum without climate control in a tropical region, included small Ère Ìbejì (twin figures), verandah posts, and monumental Epa masks over four feet in height. It was necessary to employ strategies to safely transition wooden objects from storage with high humidity to the controlled museum environment at YUAG.
This case study presents steps taken to mitigate damage including packing objects to minimize condensation resulting from temperature changes in transit; acclimatizing objects in a purpose-built sealed chamber in which the RH could gradually be lowered; and narrowing the RH range in the exhibition gallery to lessen the drop for the loans from Lagos, while adhering to the loan requirements of other lending institutions. The decision-making process, based on research into allowable RH fluctuations for wooden objects, will also be discussed.
Material Imitation and Imitation Materials in Furniture and Conservation. Proceedings - 13th International Symposium on Wood and Furniture Conservation, 2016
The skin of rays, known as shagreen, has enjoyed several periods of popularity as a decorative su... more The skin of rays, known as shagreen, has enjoyed several periods of popularity as a decorative surface covering for furniture, as well as for small cases and boxes. Though rare, a number of English, French and colonial Dutch shagreen-covered cabinets from the seventeenth century have survived. In eighteenth century France and England, a fashion developed for green shagreen objects, produced by dying or painting the skin, or backing the shagreen with green paper. The taste for exotic materials of the Art Deco period saw another revival of the material, with Parisian cabinet makers including Émile-Jacques Ruhlmann and Jean-Michel Frank, using shagreen to great decorative effect.
After tracing the historical use of the material, this paper will examine the derivation of the term shagreen, exploring the possibility that ray skin was used by craftsmen in conscious imitation of aesthetically similar donkey hide embossed with seeds, which is described by the same word. The paper will then look at imitations of rayskin shagreen itself, produced both in response to the costs associated with the true material – caused in part by the fact that area of the skin that can be actually be used is relatively small – as well as ethical concerns surrounding the use of an increasingly endangered species. Nineteenth and twentieth centuries saw the use of printed and varnished papers and leathers, whilst vinyl and epoxy resin versions have been manufactured in more recent years. The paper will finally discuss two fill materials used by the author for the conservation of a ray skin shagreen object.
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Conference posters by Cathy Silverman
Areas of two eighteenth century American japanned chests in the collection of the Metropolitan Museum of Art were scanned using a Bruker M6 Jetstream system. Data was processed to produce elemental distribution maps. A set of samples reproducing the typical stratigraphy of eighteenth century japanned surfaces was also scanned in order to further probe certain unexpected results.
The ability to overlay elemental maps made it possible to quickly see where elements were occurring separately and together, aiding the idenification of pigments and other inorganic material. Processing the data quanititavely made it possible to differentiate between areas where the same elements appear in different ratios, which was often helpful in distinguishing between original and restoration materials. The maps also made it easier to locate areas where only a small amount of original material remained. In one case, a siginificant part of the decorative scheme hidden beneath overpaint was revealed.
The limitations inherent to the technique will also be discussed. XRF does not provide information about organic materials or layer structure. The equipment is expensive and significant time and expertise is required both to scan and to process the data. Additionally, the technique is currently only suitable for two dimensional surfaces. Although it was possible to scan areas with raised decoration, the depth of field and spot size had to be increased, resulting in a less focused image.
The scanning XRF technique was found to be a significant improvement on conventional point XRF for the technical understanding of complicated, heavily restored japanned surfaces. The technique allowed the plausible attribution of pigments, metals and other inorganic material to regions, with areas of inconsistency often being immediately evident from the elemental maps.
MA Thesis by Cathy Silverman
The influence of the addition of different sizes and concentrations of powdered and manufacturer-dispersed ZnO nanoparticles to B-72 on the optical properties of resulting films was quantified using UV-Vis spectroscopy. A visual ranking of the transparency of the coatings was also made. The most promising coatings were then compared to B-72 with and without the typical organic UV absorber, oxybenzone. Coatings were applied to glass, placed over coloured printer inks on paper and exposed for varying durations to high intensity UV-A radiation. Any colour change of the inks was measured with a colorimeter, and used as an indicator of the UV- shielding capability of the coatings over time.
The results are encouraging, with the optimum coating increasing the UV-shielding by approximately 40% compared to unmodified B-72, with acceptable loss of transmittance in the visible range. However, further research would be required before recommending any treatment based on these coatings.
Articles by Cathy Silverman
This case study presents steps taken to mitigate damage including packing objects to minimize condensation resulting from temperature changes in transit; acclimatizing objects in a purpose-built sealed chamber in which the RH could gradually be lowered; and narrowing the RH range in the exhibition gallery to lessen the drop for the loans from Lagos, while adhering to the loan requirements of other lending institutions. The decision-making process, based on research into allowable RH fluctuations for wooden objects, will also be discussed.
After tracing the historical use of the material, this paper will examine the derivation of the term shagreen, exploring the possibility that ray skin was used by craftsmen in conscious imitation of aesthetically similar donkey hide embossed with seeds, which is described by the same word. The paper will then look at imitations of rayskin shagreen itself, produced both in response to the costs associated with the true material – caused in part by the fact that area of the skin that can be actually be used is relatively small – as well as ethical concerns surrounding the use of an increasingly endangered species. Nineteenth and twentieth centuries saw the use of printed and varnished papers and leathers, whilst vinyl and epoxy resin versions have been manufactured in more recent years. The paper will finally discuss two fill materials used by the author for the conservation of a ray skin shagreen object.
Areas of two eighteenth century American japanned chests in the collection of the Metropolitan Museum of Art were scanned using a Bruker M6 Jetstream system. Data was processed to produce elemental distribution maps. A set of samples reproducing the typical stratigraphy of eighteenth century japanned surfaces was also scanned in order to further probe certain unexpected results.
The ability to overlay elemental maps made it possible to quickly see where elements were occurring separately and together, aiding the idenification of pigments and other inorganic material. Processing the data quanititavely made it possible to differentiate between areas where the same elements appear in different ratios, which was often helpful in distinguishing between original and restoration materials. The maps also made it easier to locate areas where only a small amount of original material remained. In one case, a siginificant part of the decorative scheme hidden beneath overpaint was revealed.
The limitations inherent to the technique will also be discussed. XRF does not provide information about organic materials or layer structure. The equipment is expensive and significant time and expertise is required both to scan and to process the data. Additionally, the technique is currently only suitable for two dimensional surfaces. Although it was possible to scan areas with raised decoration, the depth of field and spot size had to be increased, resulting in a less focused image.
The scanning XRF technique was found to be a significant improvement on conventional point XRF for the technical understanding of complicated, heavily restored japanned surfaces. The technique allowed the plausible attribution of pigments, metals and other inorganic material to regions, with areas of inconsistency often being immediately evident from the elemental maps.
The influence of the addition of different sizes and concentrations of powdered and manufacturer-dispersed ZnO nanoparticles to B-72 on the optical properties of resulting films was quantified using UV-Vis spectroscopy. A visual ranking of the transparency of the coatings was also made. The most promising coatings were then compared to B-72 with and without the typical organic UV absorber, oxybenzone. Coatings were applied to glass, placed over coloured printer inks on paper and exposed for varying durations to high intensity UV-A radiation. Any colour change of the inks was measured with a colorimeter, and used as an indicator of the UV- shielding capability of the coatings over time.
The results are encouraging, with the optimum coating increasing the UV-shielding by approximately 40% compared to unmodified B-72, with acceptable loss of transmittance in the visible range. However, further research would be required before recommending any treatment based on these coatings.
This case study presents steps taken to mitigate damage including packing objects to minimize condensation resulting from temperature changes in transit; acclimatizing objects in a purpose-built sealed chamber in which the RH could gradually be lowered; and narrowing the RH range in the exhibition gallery to lessen the drop for the loans from Lagos, while adhering to the loan requirements of other lending institutions. The decision-making process, based on research into allowable RH fluctuations for wooden objects, will also be discussed.
After tracing the historical use of the material, this paper will examine the derivation of the term shagreen, exploring the possibility that ray skin was used by craftsmen in conscious imitation of aesthetically similar donkey hide embossed with seeds, which is described by the same word. The paper will then look at imitations of rayskin shagreen itself, produced both in response to the costs associated with the true material – caused in part by the fact that area of the skin that can be actually be used is relatively small – as well as ethical concerns surrounding the use of an increasingly endangered species. Nineteenth and twentieth centuries saw the use of printed and varnished papers and leathers, whilst vinyl and epoxy resin versions have been manufactured in more recent years. The paper will finally discuss two fill materials used by the author for the conservation of a ray skin shagreen object.