Nanke C. Schellmann | Academy of Fine Arts Vienna (original) (raw)
Papers by Nanke C. Schellmann
Eipper, P.-B. (ed.): Handbuch der Oberflächenreinigung (Handbook of Surface Cleaning), Apr 2017
The cleaning of East Asian (urushi) lacquer surfaces is a complex task. When newly manufactured, ... more The cleaning of East Asian (urushi) lacquer surfaces is a complex task. When newly manufactured, these coatings are well known to be durable and unaffected by almost any solvents. However, with the onset of ageing, the lacquer polymer changes its properties as it degrades under the influence of UV and visible light radiation and recurring changes in relative humidity. Considering that most lacquerware in Western collections is expected to have suffered some exposure to unfavourable environmental conditions during their lifetime, the specific sensitivities of degraded lacquer surfaces have to be well understood to prevent further damage to occur during cleaning.
This chapter will give an overview on the currently practiced and recommended methods for cleaning aged and degraded lacquer surfaces. The properties of East Asian lacquer and their degradation phenomena are introduced followed by an overview of the most common types of soiling, accretions and damages observed on lacquer surfaces. To increase awareness of possible risks, specific types of lacquer and décor which may be too fragile for a straightforward application of cleaning methods are also discussed. The main section of the chapter finally presents several approaches for the safe cleaning of degraded lacquer surfaces, ranging from dry methods to the use of various organic solvents and aqueous solutions.
[in German]
Wege & Ziele - Entscheidungsprozesse in der Restaurierung. Beiträge zur 24. Tagung des ÖRV, 2015
S. Haag und R. Hölzl (ed.), Ein Ägyptisches Puzzle - Ausstellungskatalog des Kunsthistorischen Museums Wien, May 2015
The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ... more The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ancient Egyptian wooden anthropoid coffin belonging to But-har-chonsu, a chantress in the cult of Amun, who lived during the 3rd Intermediate Period (Dynasty 21/22, c. 970-900 BC). In 1893, two years after her coffin was excavated, its lid was presented to Vienna’s Kunsthistorisches Museum where it was relegated to a storage facility since its very poor condition precluded exhibition.
Part II: Realigning and stabilizing the lid’s wooden structure with carbon-fibre composite dowels
After the coffin lid’s decoration was consolidated and methods of filling the spaces between it and the wooden planks were developed as described in Part I, the wooden body itself could be restored and the conservation of the lid finalized before its return to the museum.
The wooden planks used for the body of the lid (which had been inadequately and inconsistently restored following severe structural damage) were misaligned; since this prevented restoring fragments of the decoration to their proper positions as well as reassembly of the lid’s foot, major intervention was called for. The misaligned joins of the previous restoration, fixed with modern dowels of beech wood and an excessive amount of PVAc-emulsion glue, had to be opened.
The modern dowels were carefully sawn in half, and holes were drilled in those portions of the dowels remaining in place to leave a thin shell-like layer interposed between the wooden planks and new dowels. After the excess PVAc glue was softened with acetone gel it could be removed with a scalpel. Cavities and uneven surfaces in some dowel holes were smoothed with rabbit skin glue and Poraver.
Following disassembly it proved possible to realign the wooden planks correctly only when all of them were simultaneously joined. Old dowel holes had to be used for the new joins despite misalignment.
A new type of dowel made of composite carbon fibre embedded in epoxy resin (Araldite 2020) was developed which self-adjusted to any shape during use. These dowels were created by inserting braided carbon fibre rope into narrow latex balloons closed with a knot. Liquid epoxy resin was injected through a thin rubber tube into the balloons in the old dowel holes. When the planks were correctly reassembled, epoxy resin expanded the balloons to the exact shape of the misaligned dowel holes.
When the resin had hardened, the body was again taken apart, the balloons removed, and the wooden planks realigned once and for all, with the new dowels secured with fish glue (Artcolle) with a bit of Poraver added. Any large gaps remaining between the planks were additionally stabilized with spacers of spruce, coated with a mixture of gypsum, spherical silica-compound (Poraver, Superlite), fibres (Arbocel, Dralon), and pigment to simulate the colour of the ancient gesso layer on the lid.
New dowels of spruce were employed in the reassembly of the lid’s foot end since none of the ancient dowels were sturdy enough. Spacers and composite filling imitating the primer provided additional strength before the foot was reattached. Once the wooden construction was fully aligned and stabilized, all remaining loose fragments of decoration were returned to their original positions and fixed with Paraloid B 72 in acetone.
To wind up the project, a special mount was designed for the fragile lid so that it can be safely displayed upright in the museum. [in German]
S. Haag und R. Hölzl (ed.), Ein Ägyptisches Puzzle - Ausstellungskatalog des Kunsthistorischen Museums Wien, May 2015
The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ... more The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ancient Egyptian wooden anthropoid coffin belonging to But-har-chonsu, a chantress in the cult of Amun, who lived during the 3rd Intermediate Period (Dynasty 21/22, c. 970-900 BC). In 1893, two years after her coffin was excavated, its lid was presented to Vienna’s Kunsthistorisches Museum where it was relegated to a storage facility since its very poor condition precluded exhibition.
Part I: Developing a strategy for disassembling and stabilizing the coffin lid
The 23 pieces of wood composing the lid were butt-joined with wooden dowels and loose tongues. In antiquity, the spaces between the irregular planks were filled and the exterior surface primed before it was lavishly decorated with colourful figures on a yellow ground, as was typical for the 3rd Intermediate Period, and varnished with a natural resin.
Serious damage in the past, followed by inconsistent and incomplete restoration measures in the first half of the 20th century, rendered the lid unsuitable even for safe storage, let alone exhibition. Some incorrectly aligned planks of the wooden body had been secured with new dowels and PVAc-emulsion glue, and the gaps between the pieces filled with modern gypsum plaster. Furthermore, the foot end of the lid remained disassembled, and there were a number of loose segments of the decoration as well as pieces of wood that could not be incorporated because others had been incorrectly aligned.
The goal of the project was to reassemble the lid correctly in its entirety and to consolidate the decoration, which had separated from the wood, by filling any cavities that had formed below the layer of gesso. The first step was to ‘de-restore’ the lid. To enable repositioning and reassembly of the wooden planks and the loose fragments of decoration, all the gypsum plaster had to be removed. Only then were the modern dowels supporting the incorrectly aligned planks accessible. To support the lid and ensure its stability during this process, a temporary framework was created that facilitated access from every angle.
Before proceeding to realign the planks (described in Part II), the polychrome decoration and the layer of gesso were consolidated with a mixture of isinglass and funori with white spirit added to render the sensitive paint layer water repellent. To reattach fragments, Paraloid B72 was employed, at times with micro bubbles of glass which were also used with rabbit-skin glue for filling cavities between the gesso layer and the wood underneath it. To replace the ordinary stiff gypsum plaster previously employed to fill gaps between joins, a new material was developed, binding the silica compounds Perlite and Poraver with gypsum.
Implementation of a detailed, step-by-step strategy in the initial phase of consolidating the decoration ensured that that the wooden planks could be appropriately and carefully separated preparatory to realignment and final reassembly of all loose pieces of decoration (q.v. Part II). [in German]
Journal of Materials Science, Jan 2015
In the field of cultural objects conservation efficient stabilisation of fragile and failing, mul... more In the field of cultural objects conservation efficient stabilisation of fragile and failing, multilayered decorative coatings is a complex and challenging task. This paper introduces a new application of the standardised double-cantilever beam (DCB) test method to improve the understanding of the mechanical properties of failing material and to determine the effect of polymeric agents (consolidants) added for their stabilisation. The adapted DCB method was used to measure the fracture energy, G Ic, and the fracture behaviour of brittle, protein-bound (gesso-type) foundation layers on wooden substrates that typically suffer from delamination and flaking. Wooden DCB specimens containing a brittle layer of protein glue mixed with finely ground clay powder were prepared, fractured, then consolidated with a range of commonly used polymer formulations and finally re-fractured to provide measurements for direct comparison. Consolidants tested included gelatine-based glues (bovine hide glue, isinglass; both pre-stained with Fast Green dye), acrylics (Lascaux Medium for Consolidation, Paraloid B-72/B-48N), poly(vinyl acetates) (Mowilith 50, Mowilith DMC2) and poly(vinyl alcohol) (Mowiol 3-83). Before second-phase fracture cross-sections were taken from the DCB specimens for determining penetration depth and gap-filling ability. For better visibility, the specimens containing acrylics were stained with Solvent blue G dye; iodine-potassium iodide was used for staining the other synthetic consolidants. The resulting data showed that the test method could determine measurable differences between initial G Ic (47 ± 22 J/m2) and post-consolidation G Ic values. Also, penetration behaviour could be well characterised and valuable, and detailed information on the type and location of crack path propagation was gained.
Studies in Conservation 59, 2014
Doctoral thesis, Academy of Fine Arts Dresden, Germany., 2012
Determining the performance of polymeric consolidants for fragile, multilayered decorative coatin... more Determining the performance of polymeric consolidants for fragile, multilayered decorative coatings is a great challenge. A new method is presented to detail the mechanical strengthening effect consolidants have on coating structures. Research was undertaken using East Asian lacquer coatings as an example of multilayered coatings showing brittle fracture and delamination.
A survey identified gesso-type foundation layers to be the least stable layers in the coatings. Mechanical strength tests performed with the standardised double cantilever beam (DCB) method measured the fracture energy (GIc) to characterise the fracture behaviour of the brittle layer. DCB specimens were fractured, then consolidated with polymer formulations and re-fractured to provide data for direct comparison. Consolidants included hide glue, cold-liquid fish glue, isinglass, starch/isinglass, Lascaux Medium for Consolidation (MfK), Paraloid B72 and B48N, Mowiol 3-83, Mowilith 50 and DMC2, and East Asian lacquer (urushi). For undamaged foundation layers, GIc=47(±22) J/m2 was measured. Results for consolidated specimens varied widely. Paraloid and fish glue showed great decreases in mean GIc (down to - 98 %), Lascaux MfC and Mowilith DMC2 gave the greatest increases (up to +180%). Further information on the penetration and void-filling ability of consolidants was provided by cross-sections of the DCB specimens, which matched the results of the measured GIc.
The results showed that differences in the fracture energy, the penetration behaviour of the consolidants, and the location of crack path propagation are measurable using the DCB method. These data provide a much improved understanding of the strengthening capability of different consolidants.
A fracture mechanics approach for analysing failing multilayered decorative coatings on wood Preprints of Papers presented at the ICOM-CC 16th Triennial Meeting, Lisbon, Portugal, 19-23 September 2011. ICOM-CC, Lisbon, 2011
Determining the efficiency and performance of polymer formulations used as consolidants for fragi... more Determining the efficiency and performance of polymer formulations used as consolidants for fragile, multilayered decorative coatings is often a great challenge in conservation. This paper introduces a new application of the standardised double cantilever beam (DCB) test method used in fracture mechanics as an improved means to tackle this problem. The adapted DCB method was employed to determine the independent material property fracture energy, GIc, and the fracture behaviour of brittle, protein-bound (gesso-type) foundation layers on wooden substrates that typically suffer from delamination and flaking. DCB specimens containing the brittle foundation layer between wooden beams were prepared. Once fractured, the specimens were consolidated with different polymer formulations and re-fractured to provide data for direct comparison. The results showed that the method could determine measurable differences in fracture energy, and also supply valuable and detailed information on change...
Online Proceedings of the CCI Symposium 2011 - Adhesives & Consolidants for Conservation: Research & Applications, Ottawa, 17-21 Oct 2011. CCI, Ottawa, Oct 2011
Determining the efficiency and performance of polymer formulations used as consolidants for fragi... more Determining the efficiency and performance of polymer formulations used as consolidants for fragile, multilayered decorative coatings is often a great challenge in conservation. This paper reports the results of tests that investigated the performance of a variety of consolidants for the stabilization of such coatings. East Asian lacquer coatings were used as a typical representative of multilayered coatings with protein-bound (gesso-type) foundation layers that show brittle fracture, delamination, and flaking. Mechanical strength tests were undertaken with a fracture mechanics approach using the standardized double cantilever beam (DCB) method. The independent material property fracture energy, GIc, was measured, and the fracture behaviour of the brittle, protein-bound foundation layers was determined. DCB specimens were prepared, fractured, then consolidated with a variety of polymer formulations and re-fractured to provide data for direct comparison. The tested consolidants inclu...
S. Rivers, R. Faulkner and B. Pretzel, Crossing Borders: The Conservation, Science and Material Culture of East Asian Lacquer. Archetype, London, pp. 107-120., 2011
East Asian lacquer objects from the collection of the Victoria and Albert Museum were subjected t... more East Asian lacquer objects from the collection of the Victoria and Albert Museum were subjected to microscopic cross-sectional and FTIR analysis to determine possible causes for delaminating and flaking of coatings. The results give some indication of the different failure types that may occur in East Asian lacquer structures and will provide a clearer picture of failure mechanisms in multilayered export lacquer structures, thereby helping to find appropriate consolidation treatments for flaking lacquer coatings. Delamination occurs predominantly at or near the interface of lower foundation layers that are bound with a low lacquer concentration or cheaper surrogates. Cohesion and some adhesion failure of foundations that contain protein or starch was found to be the most common cause for flaking of East Asian export lacquer coatings. Layers with high lacquer concentration show good cohesion and adhesion to their adjacent foundations, paper and textile layers and lacquer films.
Victoria and Albert Museum Conservation Journal, 2008
East Asian lacquer coatings are complex multilayered structures, usually consisting of several fo... more East Asian lacquer coatings are complex multilayered structures, usually consisting of several foundation layers, sometimes incorporating sheets of textile or paper, followed by a number of lacquer top coats to produce a highly polished surface. The main rationale behind this ...
IIC Reviews in Conservation 8, pp. 55-66., 2007
Collagen-based animal glues are widely used in the conservation of artefacts, serving as adhesive... more Collagen-based animal glues are widely used in the conservation of artefacts, serving as adhesives, binders and consolidants for organic and inorganic materials. With a variety of different animal glues on the market, such as hide and bone glues, fish glues, isinglass and gelatin, their individual properties need to be well understood in order to choose a glue fit for a specific purpose. This paper reviews a wide range of publications on currently available animal glues, with respect to their specific physical, chemical and mechanical properties.
Zeitschrift für Kunsttechnologie und Konservierung 19(2), pp. 369 – 376., 2005
Master of Arts thesis, Royal College of Arts / Victoria and Albert Museum (RCA/V&A) Joint Conservation Programme, London, Jul 2003
V&A Conservation Journal 42, pp. 9-11, 2002
Posters by Nanke C. Schellmann
The detailed characterization of multilayered Asian lacquer coatings is an important task for con... more The detailed characterization of multilayered Asian lacquer coatings is an important task for conservators in order to develop informed conservation and restoration approaches for complex Asian objects equipped with such decorative coatings. Of particular interest is often the identification of organic binders and their distribution within the layer structure. These days, the binding media contained in the individual lacquer layers are usually identified with sophisticated analytical equipment that is capable of great detail and precision, such as Fourier-transform infrared spectroscopy or pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). However, the downside of using these techniques is that they are costly and not always accessible for many conservators, particularly at times when resources are tight. Alternative, low-tech methods that can be executed by the conservator himself are indeed available, but they are often deemed rather imprecise and potentially unreliable. Th...
Poster presented at the Asian Lacquer International Symposium, SUNY Buffalo State, 20-24 May 2013, Buffalo, New York , May 2013
The detailed characterization of multilayered Asian lacquer coatings is an important task for con... more The detailed characterization of multilayered Asian lacquer coatings is an important task for conservators in order to develop informed conservation and restoration approaches for complex Asian objects equipped with such decorative coatings. Of particular interest is often the identification of organic binders and their distribution within the layer structure. These days, the binding media contained in the individual lacquer layers are usually identified with sophisticated analytical equipment that is capable of great detail and precision, such as Fourier-transform infrared spectroscopy or pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). However, the downside of using these techniques is that they are costly and not always accessible for many conservators, particularly at times when resources are tight. Alternative, low-tech methods that can be executed by the conservator himself are indeed available, but they are often deemed rather imprecise and potentially unreliable. Th...
Postprints of the ICOM-CC Working Group Art Technological Source Research, 6th Symposium: 'Sources on Art Technology: Back to Basics', forthcoming.
Reconstructing historical stringed instruments on the basis of a single surviving specimen faces ... more Reconstructing historical stringed instruments on the basis of a single surviving specimen faces many limitations and can be problematic. Firstly, the small number of surviving historical instruments does not well represent their former diversity in style. Furthermore, the survival of these instruments after all is owed to the fact that they were, over centuries, altered and adapted to the current musical needs, resulting in the loss of their original build. Finally, modern violin making has developed certain standards that cannot be applied to historical practice, hence clouding our perception of historical viol making.
A viola da gamba by Gasparo da Salò of the Kunsthistorisches Museum Wien, built in Brescia around 1580 and repeatedly altered over time, served as a test object for reconstructing an instrument's original state aided by historical sources. The starting point was the unusual, round (i.e. without corners) body shape which has entirely vanished from the modern and historical idea of stringed instrument making. This shape points to the origins of the gamba at around 1500 in Italy and to its common ancestry with the modern guitar, confirmed by their iconography. The gamba's unusual body shape can be explained by the aesthetic idea of integral division ratios prevailing in the 16th century, which, for example, finds its expression in the “Quattro libri dell' architettura” by Andrea Palladio. Sylvestro Ganassis’ “Regola Rubertina” (Venice, 1542/43) reveals how important these aesthetics must have been for instrument making: since music is part of the quadrivium of the seven liberal arts, instruments, too, have to meet the detailed aesthetic requirements of classical education.
Whilst the gamba's body was well preserved, its setting - i.e. the pegbox, neck, fretboard, bridge and tailpiece - remained questionable, as well as its relation to the instrument’s structural geometry. Answers are found in Northern Italian paintings from 1580 as well as in illustrations and written information from later musical treatises, such as the “Syntagma musicum” by Michael Praetorius or the “Harmonie universelle” by Marin Mersenne. Until recently, depictions of instruments on frontispieces of printed sheet music were entirely neglected as a source of information. Using these sources, many questions, e.g. regarding the original size of the neck and the shape of the fretboard, could be answered. It is also apparent that in 16th - 18th century paintings the bridge position deviates strongly from the one required in modern violin making. In this regard Ganassi, Mersenne, Praetorius, and James Talbot (around 1680) suggest a potential connection with the strictly geometrical soundbox construction. Further detailed information is found in 16th century paintings showing stringed instruments with strongly bent pegboxes, which resemble lutes. These also hint at an early relation between lutes and gambas.
This presentation critically rates these findings under the aspect of the traditions of contemporary performance practice and technology. Using the particular features of the mentioned instrument as well as the available sources, potential solutions for so far unresolved questions are proposed and a replica is presented, where all the current findings were carried into effect.
ICOM-CC Interim Meeting "Heritage Wood: Research & Conservation in the 21st Century", Oct 2013
""This case study focuses on the development of a systematic approach for the de-restoration and ... more ""This case study focuses on the development of a systematic approach for the de-restoration and reassembly of an ancient Egyptian anthropoid wooden coffin lid belonging to the coffin of the Egyptian priestess But-haar-chons from the 3rd Intermediate Period, Dynasty 21/22 (c. 970-890 B.C.E.). The coffin was excavated in 1891 together with a large number of other coffins from a tomb known as The Second Find of Deir el Bahari, which was built for the priests of Amun from Thebes. In 1893, the coffin lid was donated to the Kunsthistorisches Museum, Vienna, but was kept in museum storage ever since due to its badly damaged condition.
The coffin lid is constructed of 23 wood sections that are edge- joined together, with loose tongues and dowels, and the cavities of the rough wooden surface are filled and covered with a preparation layer (earthen material). The exterior of the lid is lavishly decorated with multicoloured figures on yellow ground and coated with a typical brilliant yellowing varnish. However, due to serious structural damage that occurred in the past followed by an inconsistent and incomplete restoration measure executed sometime during the 20th C., the coffin presents itself in a state entirely unfit for display or safe storage. Some of the wood sections of the carcass were inappropriately aligned and fixed with new dowels and an excessive amount of PVAc-emulsion glue, whilst the gaps between the wood sections were filled with modern gypsum plaster. At the same time, the stilt (foot of the coffin) was left entirely disassembled and a large number of loose coating fragments and slabs deriving from various locations of the coffin lid were still kept as loose elements. These fragments could not be relocated due to the inappropriate alignment of the carcass.
The goal of the current intervention and conservation is to enable a correct and complete reassembly of all existing structural and decorative elements, as well as the structural consolidation and filling of the cavities underneath the preparation layer. To achieve this, a substantial de-restoration of the coffin lid is required.
In order to reposition and reassemble the entire wooden structure and the loose coating fragments, all the gypsum plaster had to be removed from the joints. This was necessary to access the modern dowels used for stabilizing the falsely aligned wood sections. To keep the coffin lid stable during the disassembly process, a secondary supporting structure was developed that allows access from all directions.
Before focusing on readjusting the unaligned wood sections, the paint layers were consolidated with a mixture of isinglass and funori using white spirit to make the water sensitive paint layer hydrophobic. The filling of the gaps between the thick preparation layer and the wood was performed with glass micro-balloons and rabbit skin glue. As a replacement for the ordinary stiff gypsum plaster filler previously used for the large gaps between the joints, a new filling material was developed using the silica-compounds Perlite® and Poraver® bound with gypsum.
This preliminary stage in the de-restoration of the coffin lid now enables the development of a detailed step-by-step strategy to ensure the proper and non-destructive disconnection and alignment of the wooden sections followed by the reassembly of all loose paint fragments.""
Eipper, P.-B. (ed.): Handbuch der Oberflächenreinigung (Handbook of Surface Cleaning), Apr 2017
The cleaning of East Asian (urushi) lacquer surfaces is a complex task. When newly manufactured, ... more The cleaning of East Asian (urushi) lacquer surfaces is a complex task. When newly manufactured, these coatings are well known to be durable and unaffected by almost any solvents. However, with the onset of ageing, the lacquer polymer changes its properties as it degrades under the influence of UV and visible light radiation and recurring changes in relative humidity. Considering that most lacquerware in Western collections is expected to have suffered some exposure to unfavourable environmental conditions during their lifetime, the specific sensitivities of degraded lacquer surfaces have to be well understood to prevent further damage to occur during cleaning.
This chapter will give an overview on the currently practiced and recommended methods for cleaning aged and degraded lacquer surfaces. The properties of East Asian lacquer and their degradation phenomena are introduced followed by an overview of the most common types of soiling, accretions and damages observed on lacquer surfaces. To increase awareness of possible risks, specific types of lacquer and décor which may be too fragile for a straightforward application of cleaning methods are also discussed. The main section of the chapter finally presents several approaches for the safe cleaning of degraded lacquer surfaces, ranging from dry methods to the use of various organic solvents and aqueous solutions.
[in German]
Wege & Ziele - Entscheidungsprozesse in der Restaurierung. Beiträge zur 24. Tagung des ÖRV, 2015
S. Haag und R. Hölzl (ed.), Ein Ägyptisches Puzzle - Ausstellungskatalog des Kunsthistorischen Museums Wien, May 2015
The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ... more The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ancient Egyptian wooden anthropoid coffin belonging to But-har-chonsu, a chantress in the cult of Amun, who lived during the 3rd Intermediate Period (Dynasty 21/22, c. 970-900 BC). In 1893, two years after her coffin was excavated, its lid was presented to Vienna’s Kunsthistorisches Museum where it was relegated to a storage facility since its very poor condition precluded exhibition.
Part II: Realigning and stabilizing the lid’s wooden structure with carbon-fibre composite dowels
After the coffin lid’s decoration was consolidated and methods of filling the spaces between it and the wooden planks were developed as described in Part I, the wooden body itself could be restored and the conservation of the lid finalized before its return to the museum.
The wooden planks used for the body of the lid (which had been inadequately and inconsistently restored following severe structural damage) were misaligned; since this prevented restoring fragments of the decoration to their proper positions as well as reassembly of the lid’s foot, major intervention was called for. The misaligned joins of the previous restoration, fixed with modern dowels of beech wood and an excessive amount of PVAc-emulsion glue, had to be opened.
The modern dowels were carefully sawn in half, and holes were drilled in those portions of the dowels remaining in place to leave a thin shell-like layer interposed between the wooden planks and new dowels. After the excess PVAc glue was softened with acetone gel it could be removed with a scalpel. Cavities and uneven surfaces in some dowel holes were smoothed with rabbit skin glue and Poraver.
Following disassembly it proved possible to realign the wooden planks correctly only when all of them were simultaneously joined. Old dowel holes had to be used for the new joins despite misalignment.
A new type of dowel made of composite carbon fibre embedded in epoxy resin (Araldite 2020) was developed which self-adjusted to any shape during use. These dowels were created by inserting braided carbon fibre rope into narrow latex balloons closed with a knot. Liquid epoxy resin was injected through a thin rubber tube into the balloons in the old dowel holes. When the planks were correctly reassembled, epoxy resin expanded the balloons to the exact shape of the misaligned dowel holes.
When the resin had hardened, the body was again taken apart, the balloons removed, and the wooden planks realigned once and for all, with the new dowels secured with fish glue (Artcolle) with a bit of Poraver added. Any large gaps remaining between the planks were additionally stabilized with spacers of spruce, coated with a mixture of gypsum, spherical silica-compound (Poraver, Superlite), fibres (Arbocel, Dralon), and pigment to simulate the colour of the ancient gesso layer on the lid.
New dowels of spruce were employed in the reassembly of the lid’s foot end since none of the ancient dowels were sturdy enough. Spacers and composite filling imitating the primer provided additional strength before the foot was reattached. Once the wooden construction was fully aligned and stabilized, all remaining loose fragments of decoration were returned to their original positions and fixed with Paraloid B 72 in acetone.
To wind up the project, a special mount was designed for the fragile lid so that it can be safely displayed upright in the museum. [in German]
S. Haag und R. Hölzl (ed.), Ein Ägyptisches Puzzle - Ausstellungskatalog des Kunsthistorischen Museums Wien, May 2015
The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ... more The project focused on the development of a method to ‘de-restore’ and reassemble the lid of the ancient Egyptian wooden anthropoid coffin belonging to But-har-chonsu, a chantress in the cult of Amun, who lived during the 3rd Intermediate Period (Dynasty 21/22, c. 970-900 BC). In 1893, two years after her coffin was excavated, its lid was presented to Vienna’s Kunsthistorisches Museum where it was relegated to a storage facility since its very poor condition precluded exhibition.
Part I: Developing a strategy for disassembling and stabilizing the coffin lid
The 23 pieces of wood composing the lid were butt-joined with wooden dowels and loose tongues. In antiquity, the spaces between the irregular planks were filled and the exterior surface primed before it was lavishly decorated with colourful figures on a yellow ground, as was typical for the 3rd Intermediate Period, and varnished with a natural resin.
Serious damage in the past, followed by inconsistent and incomplete restoration measures in the first half of the 20th century, rendered the lid unsuitable even for safe storage, let alone exhibition. Some incorrectly aligned planks of the wooden body had been secured with new dowels and PVAc-emulsion glue, and the gaps between the pieces filled with modern gypsum plaster. Furthermore, the foot end of the lid remained disassembled, and there were a number of loose segments of the decoration as well as pieces of wood that could not be incorporated because others had been incorrectly aligned.
The goal of the project was to reassemble the lid correctly in its entirety and to consolidate the decoration, which had separated from the wood, by filling any cavities that had formed below the layer of gesso. The first step was to ‘de-restore’ the lid. To enable repositioning and reassembly of the wooden planks and the loose fragments of decoration, all the gypsum plaster had to be removed. Only then were the modern dowels supporting the incorrectly aligned planks accessible. To support the lid and ensure its stability during this process, a temporary framework was created that facilitated access from every angle.
Before proceeding to realign the planks (described in Part II), the polychrome decoration and the layer of gesso were consolidated with a mixture of isinglass and funori with white spirit added to render the sensitive paint layer water repellent. To reattach fragments, Paraloid B72 was employed, at times with micro bubbles of glass which were also used with rabbit-skin glue for filling cavities between the gesso layer and the wood underneath it. To replace the ordinary stiff gypsum plaster previously employed to fill gaps between joins, a new material was developed, binding the silica compounds Perlite and Poraver with gypsum.
Implementation of a detailed, step-by-step strategy in the initial phase of consolidating the decoration ensured that that the wooden planks could be appropriately and carefully separated preparatory to realignment and final reassembly of all loose pieces of decoration (q.v. Part II). [in German]
Journal of Materials Science, Jan 2015
In the field of cultural objects conservation efficient stabilisation of fragile and failing, mul... more In the field of cultural objects conservation efficient stabilisation of fragile and failing, multilayered decorative coatings is a complex and challenging task. This paper introduces a new application of the standardised double-cantilever beam (DCB) test method to improve the understanding of the mechanical properties of failing material and to determine the effect of polymeric agents (consolidants) added for their stabilisation. The adapted DCB method was used to measure the fracture energy, G Ic, and the fracture behaviour of brittle, protein-bound (gesso-type) foundation layers on wooden substrates that typically suffer from delamination and flaking. Wooden DCB specimens containing a brittle layer of protein glue mixed with finely ground clay powder were prepared, fractured, then consolidated with a range of commonly used polymer formulations and finally re-fractured to provide measurements for direct comparison. Consolidants tested included gelatine-based glues (bovine hide glue, isinglass; both pre-stained with Fast Green dye), acrylics (Lascaux Medium for Consolidation, Paraloid B-72/B-48N), poly(vinyl acetates) (Mowilith 50, Mowilith DMC2) and poly(vinyl alcohol) (Mowiol 3-83). Before second-phase fracture cross-sections were taken from the DCB specimens for determining penetration depth and gap-filling ability. For better visibility, the specimens containing acrylics were stained with Solvent blue G dye; iodine-potassium iodide was used for staining the other synthetic consolidants. The resulting data showed that the test method could determine measurable differences between initial G Ic (47 ± 22 J/m2) and post-consolidation G Ic values. Also, penetration behaviour could be well characterised and valuable, and detailed information on the type and location of crack path propagation was gained.
Studies in Conservation 59, 2014
Doctoral thesis, Academy of Fine Arts Dresden, Germany., 2012
Determining the performance of polymeric consolidants for fragile, multilayered decorative coatin... more Determining the performance of polymeric consolidants for fragile, multilayered decorative coatings is a great challenge. A new method is presented to detail the mechanical strengthening effect consolidants have on coating structures. Research was undertaken using East Asian lacquer coatings as an example of multilayered coatings showing brittle fracture and delamination.
A survey identified gesso-type foundation layers to be the least stable layers in the coatings. Mechanical strength tests performed with the standardised double cantilever beam (DCB) method measured the fracture energy (GIc) to characterise the fracture behaviour of the brittle layer. DCB specimens were fractured, then consolidated with polymer formulations and re-fractured to provide data for direct comparison. Consolidants included hide glue, cold-liquid fish glue, isinglass, starch/isinglass, Lascaux Medium for Consolidation (MfK), Paraloid B72 and B48N, Mowiol 3-83, Mowilith 50 and DMC2, and East Asian lacquer (urushi). For undamaged foundation layers, GIc=47(±22) J/m2 was measured. Results for consolidated specimens varied widely. Paraloid and fish glue showed great decreases in mean GIc (down to - 98 %), Lascaux MfC and Mowilith DMC2 gave the greatest increases (up to +180%). Further information on the penetration and void-filling ability of consolidants was provided by cross-sections of the DCB specimens, which matched the results of the measured GIc.
The results showed that differences in the fracture energy, the penetration behaviour of the consolidants, and the location of crack path propagation are measurable using the DCB method. These data provide a much improved understanding of the strengthening capability of different consolidants.
A fracture mechanics approach for analysing failing multilayered decorative coatings on wood Preprints of Papers presented at the ICOM-CC 16th Triennial Meeting, Lisbon, Portugal, 19-23 September 2011. ICOM-CC, Lisbon, 2011
Determining the efficiency and performance of polymer formulations used as consolidants for fragi... more Determining the efficiency and performance of polymer formulations used as consolidants for fragile, multilayered decorative coatings is often a great challenge in conservation. This paper introduces a new application of the standardised double cantilever beam (DCB) test method used in fracture mechanics as an improved means to tackle this problem. The adapted DCB method was employed to determine the independent material property fracture energy, GIc, and the fracture behaviour of brittle, protein-bound (gesso-type) foundation layers on wooden substrates that typically suffer from delamination and flaking. DCB specimens containing the brittle foundation layer between wooden beams were prepared. Once fractured, the specimens were consolidated with different polymer formulations and re-fractured to provide data for direct comparison. The results showed that the method could determine measurable differences in fracture energy, and also supply valuable and detailed information on change...
Online Proceedings of the CCI Symposium 2011 - Adhesives & Consolidants for Conservation: Research & Applications, Ottawa, 17-21 Oct 2011. CCI, Ottawa, Oct 2011
Determining the efficiency and performance of polymer formulations used as consolidants for fragi... more Determining the efficiency and performance of polymer formulations used as consolidants for fragile, multilayered decorative coatings is often a great challenge in conservation. This paper reports the results of tests that investigated the performance of a variety of consolidants for the stabilization of such coatings. East Asian lacquer coatings were used as a typical representative of multilayered coatings with protein-bound (gesso-type) foundation layers that show brittle fracture, delamination, and flaking. Mechanical strength tests were undertaken with a fracture mechanics approach using the standardized double cantilever beam (DCB) method. The independent material property fracture energy, GIc, was measured, and the fracture behaviour of the brittle, protein-bound foundation layers was determined. DCB specimens were prepared, fractured, then consolidated with a variety of polymer formulations and re-fractured to provide data for direct comparison. The tested consolidants inclu...
S. Rivers, R. Faulkner and B. Pretzel, Crossing Borders: The Conservation, Science and Material Culture of East Asian Lacquer. Archetype, London, pp. 107-120., 2011
East Asian lacquer objects from the collection of the Victoria and Albert Museum were subjected t... more East Asian lacquer objects from the collection of the Victoria and Albert Museum were subjected to microscopic cross-sectional and FTIR analysis to determine possible causes for delaminating and flaking of coatings. The results give some indication of the different failure types that may occur in East Asian lacquer structures and will provide a clearer picture of failure mechanisms in multilayered export lacquer structures, thereby helping to find appropriate consolidation treatments for flaking lacquer coatings. Delamination occurs predominantly at or near the interface of lower foundation layers that are bound with a low lacquer concentration or cheaper surrogates. Cohesion and some adhesion failure of foundations that contain protein or starch was found to be the most common cause for flaking of East Asian export lacquer coatings. Layers with high lacquer concentration show good cohesion and adhesion to their adjacent foundations, paper and textile layers and lacquer films.
Victoria and Albert Museum Conservation Journal, 2008
East Asian lacquer coatings are complex multilayered structures, usually consisting of several fo... more East Asian lacquer coatings are complex multilayered structures, usually consisting of several foundation layers, sometimes incorporating sheets of textile or paper, followed by a number of lacquer top coats to produce a highly polished surface. The main rationale behind this ...
IIC Reviews in Conservation 8, pp. 55-66., 2007
Collagen-based animal glues are widely used in the conservation of artefacts, serving as adhesive... more Collagen-based animal glues are widely used in the conservation of artefacts, serving as adhesives, binders and consolidants for organic and inorganic materials. With a variety of different animal glues on the market, such as hide and bone glues, fish glues, isinglass and gelatin, their individual properties need to be well understood in order to choose a glue fit for a specific purpose. This paper reviews a wide range of publications on currently available animal glues, with respect to their specific physical, chemical and mechanical properties.
Zeitschrift für Kunsttechnologie und Konservierung 19(2), pp. 369 – 376., 2005
Master of Arts thesis, Royal College of Arts / Victoria and Albert Museum (RCA/V&A) Joint Conservation Programme, London, Jul 2003
V&A Conservation Journal 42, pp. 9-11, 2002
The detailed characterization of multilayered Asian lacquer coatings is an important task for con... more The detailed characterization of multilayered Asian lacquer coatings is an important task for conservators in order to develop informed conservation and restoration approaches for complex Asian objects equipped with such decorative coatings. Of particular interest is often the identification of organic binders and their distribution within the layer structure. These days, the binding media contained in the individual lacquer layers are usually identified with sophisticated analytical equipment that is capable of great detail and precision, such as Fourier-transform infrared spectroscopy or pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). However, the downside of using these techniques is that they are costly and not always accessible for many conservators, particularly at times when resources are tight. Alternative, low-tech methods that can be executed by the conservator himself are indeed available, but they are often deemed rather imprecise and potentially unreliable. Th...
Poster presented at the Asian Lacquer International Symposium, SUNY Buffalo State, 20-24 May 2013, Buffalo, New York , May 2013
The detailed characterization of multilayered Asian lacquer coatings is an important task for con... more The detailed characterization of multilayered Asian lacquer coatings is an important task for conservators in order to develop informed conservation and restoration approaches for complex Asian objects equipped with such decorative coatings. Of particular interest is often the identification of organic binders and their distribution within the layer structure. These days, the binding media contained in the individual lacquer layers are usually identified with sophisticated analytical equipment that is capable of great detail and precision, such as Fourier-transform infrared spectroscopy or pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). However, the downside of using these techniques is that they are costly and not always accessible for many conservators, particularly at times when resources are tight. Alternative, low-tech methods that can be executed by the conservator himself are indeed available, but they are often deemed rather imprecise and potentially unreliable. Th...
Postprints of the ICOM-CC Working Group Art Technological Source Research, 6th Symposium: 'Sources on Art Technology: Back to Basics', forthcoming.
Reconstructing historical stringed instruments on the basis of a single surviving specimen faces ... more Reconstructing historical stringed instruments on the basis of a single surviving specimen faces many limitations and can be problematic. Firstly, the small number of surviving historical instruments does not well represent their former diversity in style. Furthermore, the survival of these instruments after all is owed to the fact that they were, over centuries, altered and adapted to the current musical needs, resulting in the loss of their original build. Finally, modern violin making has developed certain standards that cannot be applied to historical practice, hence clouding our perception of historical viol making.
A viola da gamba by Gasparo da Salò of the Kunsthistorisches Museum Wien, built in Brescia around 1580 and repeatedly altered over time, served as a test object for reconstructing an instrument's original state aided by historical sources. The starting point was the unusual, round (i.e. without corners) body shape which has entirely vanished from the modern and historical idea of stringed instrument making. This shape points to the origins of the gamba at around 1500 in Italy and to its common ancestry with the modern guitar, confirmed by their iconography. The gamba's unusual body shape can be explained by the aesthetic idea of integral division ratios prevailing in the 16th century, which, for example, finds its expression in the “Quattro libri dell' architettura” by Andrea Palladio. Sylvestro Ganassis’ “Regola Rubertina” (Venice, 1542/43) reveals how important these aesthetics must have been for instrument making: since music is part of the quadrivium of the seven liberal arts, instruments, too, have to meet the detailed aesthetic requirements of classical education.
Whilst the gamba's body was well preserved, its setting - i.e. the pegbox, neck, fretboard, bridge and tailpiece - remained questionable, as well as its relation to the instrument’s structural geometry. Answers are found in Northern Italian paintings from 1580 as well as in illustrations and written information from later musical treatises, such as the “Syntagma musicum” by Michael Praetorius or the “Harmonie universelle” by Marin Mersenne. Until recently, depictions of instruments on frontispieces of printed sheet music were entirely neglected as a source of information. Using these sources, many questions, e.g. regarding the original size of the neck and the shape of the fretboard, could be answered. It is also apparent that in 16th - 18th century paintings the bridge position deviates strongly from the one required in modern violin making. In this regard Ganassi, Mersenne, Praetorius, and James Talbot (around 1680) suggest a potential connection with the strictly geometrical soundbox construction. Further detailed information is found in 16th century paintings showing stringed instruments with strongly bent pegboxes, which resemble lutes. These also hint at an early relation between lutes and gambas.
This presentation critically rates these findings under the aspect of the traditions of contemporary performance practice and technology. Using the particular features of the mentioned instrument as well as the available sources, potential solutions for so far unresolved questions are proposed and a replica is presented, where all the current findings were carried into effect.
ICOM-CC Interim Meeting "Heritage Wood: Research & Conservation in the 21st Century", Oct 2013
""This case study focuses on the development of a systematic approach for the de-restoration and ... more ""This case study focuses on the development of a systematic approach for the de-restoration and reassembly of an ancient Egyptian anthropoid wooden coffin lid belonging to the coffin of the Egyptian priestess But-haar-chons from the 3rd Intermediate Period, Dynasty 21/22 (c. 970-890 B.C.E.). The coffin was excavated in 1891 together with a large number of other coffins from a tomb known as The Second Find of Deir el Bahari, which was built for the priests of Amun from Thebes. In 1893, the coffin lid was donated to the Kunsthistorisches Museum, Vienna, but was kept in museum storage ever since due to its badly damaged condition.
The coffin lid is constructed of 23 wood sections that are edge- joined together, with loose tongues and dowels, and the cavities of the rough wooden surface are filled and covered with a preparation layer (earthen material). The exterior of the lid is lavishly decorated with multicoloured figures on yellow ground and coated with a typical brilliant yellowing varnish. However, due to serious structural damage that occurred in the past followed by an inconsistent and incomplete restoration measure executed sometime during the 20th C., the coffin presents itself in a state entirely unfit for display or safe storage. Some of the wood sections of the carcass were inappropriately aligned and fixed with new dowels and an excessive amount of PVAc-emulsion glue, whilst the gaps between the wood sections were filled with modern gypsum plaster. At the same time, the stilt (foot of the coffin) was left entirely disassembled and a large number of loose coating fragments and slabs deriving from various locations of the coffin lid were still kept as loose elements. These fragments could not be relocated due to the inappropriate alignment of the carcass.
The goal of the current intervention and conservation is to enable a correct and complete reassembly of all existing structural and decorative elements, as well as the structural consolidation and filling of the cavities underneath the preparation layer. To achieve this, a substantial de-restoration of the coffin lid is required.
In order to reposition and reassemble the entire wooden structure and the loose coating fragments, all the gypsum plaster had to be removed from the joints. This was necessary to access the modern dowels used for stabilizing the falsely aligned wood sections. To keep the coffin lid stable during the disassembly process, a secondary supporting structure was developed that allows access from all directions.
Before focusing on readjusting the unaligned wood sections, the paint layers were consolidated with a mixture of isinglass and funori using white spirit to make the water sensitive paint layer hydrophobic. The filling of the gaps between the thick preparation layer and the wood was performed with glass micro-balloons and rabbit skin glue. As a replacement for the ordinary stiff gypsum plaster filler previously used for the large gaps between the joints, a new filling material was developed using the silica-compounds Perlite® and Poraver® bound with gypsum.
This preliminary stage in the de-restoration of the coffin lid now enables the development of a detailed step-by-step strategy to ensure the proper and non-destructive disconnection and alignment of the wooden sections followed by the reassembly of all loose paint fragments.""
Staatliche Akademie der Bildenden Künste Stuttgart, 2016
The presentation introduced a novel method for evaluating the performance of different consolidat... more The presentation introduced a novel method for evaluating the performance of different consolidation treatments for decorated wooden artefacts.
In conservation, many different methods and adhesives are used with varying results for the consolidation of wood and their decorative surfaces. In order to evaluate the behaviour and effectiveness of different adhesive media, a novel method was developed that ascertains whether and how some vital mechanical properties of the fragile substrate change with consolidation treatment.
The test method establishes the fracture characteristics of the material before and after consolidation by adapting a recognised test method for determining the fracture toughness of adhesively bonded metal joints. The fracture toughness describes the material’s resistance to crack propagation, which is a vital criterion for evaluating the strengthening of a stressed material by a certain treatment. This test method is thus considered to give a much better and more realistic understanding of the material’s strength behaviour than conventional tensile and shear tests. While this novel method was developed using the example of flaking decorative Japanese Export lacquer coatings from wooden substrates, it also appears to be a promising means for analysing the changing toughness characteristics of wood consolidated with various adhesives.
ConNext Student Conference, 2023
Sources on art technology : back to basics : proceedings of the sixth symposium of the ICOM-CC Working Group for Art Technological Source Research, held at the Rijksmuseum, Amsterdam, 16-17 June 2014, 2014
The detailed characterization of multilayered composite materials such as Asian lacquer coatings ... more The detailed characterization of multilayered composite materials such as Asian lacquer coatings is an important task for conservators. To understand and verify the causes for the deterioration and failure of many aged lacquer objects it is vital to precisely locate the failure zones within the layered structure and to identify the material composition of the individual layers. Based on this knowledge informed conservation approaches can be developed for these fragile objects.
This presentation is looking at possibilities of characterizing complex, multilayered Asian lacquer coatings using simple and inexpensive methods such as optical microscopy and staining of specific binding media. In recent years, many of these simple analytical methods appear to have become less popular in the field of conservation with the increasing availability and sophistication of analytical equipment that is capable of great detail and precision. However, simple methods, such as staining techniques borrowed from the field of histochemistry, are valuable as a means to produce data quickly and efficiently with the full control of the tester and without the need of great expenditure in terms of time and resources. A revisit of the staining methods will show that the use of specific stains for cross-section examination of Asian lacquer coatings combined with fluorescent microscopy is capable of yielding reliable and correct results for the identification of certain binding media types. Furthermore, these methods prove to be reliable despite previous belief that they are unsuitable for dark coloured materials. It hence appears promising to revive the popularity of these techniques at times where resources are tight and conservators aim to understand materials using less costly means.
Simple staining methods for characterizing the structure and binding media composition of Asian lacquer coatings will be presented. By examining unstained and stained cross-sections of embedded coating samples using visible and fluorescent light microscopy, layer-specific information for a number of organic materials and binding media are obtained if present in significant concentrations. It will be shown that these examination results can provide detailed information on layer structure that will benefit the understanding of lacquer coatings, their physical and chemical sensitivities and potential failure causes.
Interior and space illusion of a Parisian cabinet from around 1660 Historic interior designs a... more Interior and space illusion of a Parisian cabinet from around 1660
Historic interior designs are complex creations which may only be fully deciphered by the viewer at the time of their original creation. This is due to the fact that interior space apart from artistic aspects also implies functional aspects and is dependent on the observer’s view, which is bound to change over time. Thus, historic interiors are likely to be altered, redecorated and used for different purposes as time progresses. Conservation and restoration measures therefore frequently deal with a great variety of most complex problems which may partly have to serve and fulfill rather opposing requirements. Sometimes however, chances arise to act free of these constraints.
In this talk we presented an interior which has always been locked up, has never been redecorated nor has anyone ever walked into it. It is the very lavishly decorated interior of a cabinet, originating from Paris around 1660, which incorporates a grotto rock flanked by architectural elements with a view of landscape in the background. The variety of the materials used – stained ivory, paintings, mirrors, broken pieces of glass, corals, shells, feathers etc. – is of unusual richness and evokes one question the viewer may ask himself: what is apparently shown here and what is it in reality? It is a puzzle of form, material and meaning – that is, in short, true interior design.
Even though this interior space was comparatively safely kept inside the cabinet, its decoration elements were subject to damage and loss in the course of the centuries. This made conservation and restoration measures necessary.
Any of those measures were aimed to be subordinated to the understanding of the composition and materials’ structural assembly, which enabled today’s viewer a much clearer experience of the original fantasy space. By considering the different materials individually, it will be discussed that even seemingly simple preconditions will require a complex discussion on how to implement an adequate restoration treatment. In this talk it was explained how any change to any single material of this ensemble implied direct consequences on the entire appearance, and how it was tried to find a systematic approach within this network of interdependencies. Thus, it was shown how conservators have to have a critical look at the individual reception of an interior in order to fully appreciate the room design and do it justice. It is necessary to rediscover the unity within the diversity of the single elements, without leaving conservation ethics out of consideration.
Zusammenfassung:
Historische Raumkunstwerke sind komplexe Gebilde, deren beabsichtigte Gesamtwirkung sich wahrscheinlich nur zum Zeitpunkt ihres ersten Entstehens dem Betrachter wirklich entschlüsselt. Dies liegt zum einen darin begründet, daß sich das Auge des Betrachters mit der Zeit wandelt, zum anderen aber auch, daß der Raum selbst Veränderungen unterzogen ist. Da Raum neben allen künstlerischen auch funktionale Aspekte hat, werden historische Räume im Laufe der Zeit umdekoriert, verändert und anders genutzt. Restaurierungsmaßnahmen in solchen Räumen stehen deshalb meist vor einer Fülle von komplexen Problemen, die teilweise völlig konträren Anforderungen gerecht werden müssen. Manchmal jedoch ergibt sich die Chance, vollkommen frei von derlei Zwängen handeln zu können.
In diesem Vortrag werden wir einen Raum vorstellen, der immer abgeschlossen war, wurde nie umdekoriert und noch dazu niemals von einem Menschen betreten wurde. Es ist der sehr aufwendig gestaltete Innenraum eines Kabinettschrankes, entstanden um 1660 in Paris, der einen von architektonischen Elementen eingefaßten Grottenberg mit Ausblick in Landschaften birgt. Die Vielfalt der hier verwendeten Materialien – gefärbtes Elfenbein, Gemälde, Spiegel, Glasscherben, Korallen, Muscheln, Federn u.v.a. – ist von außergewöhnlicher Reichhaltigkeit und wirft beim Betrachter zwangsläufig eine Frage auf: Was ist hier anscheinend dargestellt und was ist es wirklich; ein Vexierspiel von Form, Material und Bedeutung - kurz ein Raumkunstwerk.
Trotz der sehr geschützten Lage des Raumes hatten seine Dekorationselemente im Laufe der Jahrhunderte zahlreiche Schäden und Verluste erlitten, die restauratorische Eingriffe erforderten. Die Konzeptfindung für diese Maßnahmen sollte sich besonders dem Ziel unterordnen, das erworbene Verständnis des Materialgefüges in Eingriffe umzusetzen, die das klarere Erleben der ursprünglich geschaffenen Phantasiewelt für den heutigen Betrachter wieder ermöglichen. Anhand des Umgangs mit den unterschiedlichen Materialien wird dargestellt, dass trotz scheinbar so einfacher Vorbedingungen Abwägungen restauratorischer Art komplexe Formen annehmen können. Wir werden erläutern, wie jede Veränderung an einem einzelnen Material direkte Konsequenzen auf das Escheinungsbild des Ganzen impliziert, und wie wir in diesem Netzwerk von Interdependenzen eine Systematik zu entwickeln versucht haben. So soll verdeutlicht werden, wie der Restaurator sich mit der individuellen Rezeption des Kunstwerks auseinandersetzen muss, um der Gestaltungsidee eines Raumes gerecht zu werden. Es gilt, die Einheit in der Vielfalt der Einzelelemente wiederzufinden, ohne dabei restauratorisch/ethische Aspekte außer Acht zu lassen.