MA Thesis, Conservation and Restoration of Ceramics, Glass and Stone
Research into the Deterioration of Lacquer Decoration on a Japanese Porcelain Bowl from
Huis ten Bosch Palace
S T U D E N T | Julia Wagner 11648554
SUMMARY
Research into the Deterioration of Lacquer Decoration on a Japanese Porcelain Bowl from Huis ten Bosch Palace
Julia Wagner (11648554)
MA Thesis, Conservation and Restoration of Ceramics, Glass and Stone University of Amsterdam
28-06-2019
This thesis examined the deterioration of lacquer decoration on porcelain of a Japanese offering dish from Huis ten Bosch Palace (Royal Collection/Het Loo Palace) from the nineteenth century, and how far the difference in lacquer deterioration of the more degraded outside compared to the inside, is related to production technique.
The art historical and technological context, current knowledge about Japanese and European lacquers as well as the object’s background were investigated through literature and archival research. Experts in the field of art history, lacquer conservators and conservation scientists were consulted during the interpretation of the production, the deterioration and the analytical results.
To understand the possible causes for lacquer detachment, non-destructive and destructive analytical techniques were applied. pXRF provided information on the ceramic (substrate) and the non-organic materials used in the lacquer decoration. Information about the layered structure was obtained by studying cross sections from three lacquer samples using microscopy. THM GC-MS analysis was applied to discern the lacquer type (Asian or European) as well as other organic materials. Inorganic components and the grain structure (ground) were analysed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The structure and components of samples from the inside of the bowl were compared with samples from the outside to investigate differences in techniques and/or materials.
All the analysed lacquer layers contained urushi indicating an Asian origin. The presence of unexpected binding media such as animal glue within most lacquer layers and gum benzoin within one of the ground layers, and whether that could be from treatments or manufacture, is discussed with relation to their location and findings from literature.
While the materials and technique used may have influenced the differences in deterioration, it may also have been influenced by the conditions the object was exposed to, or, more likely, a combination of both. The probability of combined factors contributing to the current condition are put in context through findings from archival research, art historical background as well as literature on lacquered porcelain from the early 1700s, adding to the knowledge about this special group of nineteenth century lacquered porcelain that has had little attention to date. From the information gained, preservation guidelines were established, a basis for formulating a conservation strategy, and possibilities for further research proposed.
SAMENVATTING
Research into the Deterioration of Lacquer Decoration on a Japanese Porcelain Bowl from Huis ten Bosch Palace
Julia Wagner (11648554)
MA Thesis, Conservation and Restoration of Ceramics, Glass and Stone University of Amsterdam
28-06-2019
Deze scriptie onderzoekt de aantasting van de lakversiering op porselein op een negentiende-eeuwse Japanse schaal uit de Koninklijke Collectie van het Huis ten Bosch Paleis/Het Loo, en in hoeverre het verschil in lakdegradatie van de meer aangetaste buitenzijde ten opzichte van de binnenzijde gerelateerd is aan de productietechniek.
De kunsthistorische en technologische context, de huidige kennis over Japanse en Europese lakken en de achtergrond van het object zijn onderzocht door middel van literatuur- en archiefonderzoek. Kunsthistorici, restauratoren van lakwerk en conserveringswetenschappers werden geraadpleegd tijdens de interpretatie van de productie, de achteruitgang en de analytische resultaten.
Om mogelijke oorzaken van de afschilferen van de lak te begrijpen, werden niet-destructieve en destructieve analysetechnieken toegepast. pXRF gaf informatie over het keramiek (substraat) en de niet-organische materialen die gebruikt werden in de lakdecoratie. Informatie over de gelaagde structuur werd verkregen door het bestuderen van dwarsdoorsneden van drie lakmonsters met behulp van microscopie. THM GC-MS analyse werd toegepast om het type lak (Aziatisch of Europees) en andere organische materialen te onderscheiden. Anorganische componenten en de korrelstructuur (grondlaag) werden geanalyseerd met behulp van SEM-EDX. De structuur en componenten van monsters van de binnenzijde van de schaal werden vergeleken met monsters van de buitenkant om verschillen in technieken en/of materialen te onderzoeken.
Alle geanalyseerde laklagen bevatten urushi (en zijn dus van Aziatische oorsprong). De aanwezigheid van onverwachte bindmiddelen zoals dierlijke lijm in de meeste laklagen en gombenzoë in één van de grondlagen, en of dat afkomstig kan zijn van behandelingen of productie, werd besproken in relatie tot hun locatie en de bevindingen uit de literatuur. Hoewel de gebruikte materialen en technieken de verschillen in degradatie kunnen hebben beïnvloed, kunnen ook de condities waaraan het object is blootgesteld, of, waarschijnlijker, een combinatie van beide de degradatie hebben beïnvloed. De waarschijnlijkheid dat gecombineerde factoren bijdragen aan de huidige conditie wordt gecontextualiseerd door bevindingen uit archiefonderzoek, kunsthistorische achtergronden en literatuur over gelakt porselein uit het begin van de jaren 1700, waardoor de kennis over deze bijzondere groep van negentiende-eeuws gelakt porselein, die tot op heden weinig aandacht heeft gehad, nog verder wordt vergroot. Op basis van de verkregen informatie zijn richtlijnen voor de conservering opgesteld, een basis voor het formuleren van een conserveringsstrategie en mogelijkheden voor verder onderzoek voorgesteld.
TABLE OF CONTENTS 1. Introduction 5 2. The Object 6 2.1. Description 6 2.2. Condition 7 2.3. Background 9 3. Previous Research and Available Sources 11
4. Art-Historical Context 12
5. Materials and Production of Porcelain and Lacquer 14
5.1. Porcelain 14
5.1.1. Japan 15
5.1.2. Europe 16
5.2. Lacquer and Ground Constituents 16
5.2.1. Japan 16
5.2.2. Europe 25
6. Properties and Deterioration 25
6.1. Japanese Lacquer 25
6.2. European Lacquers 30
7. Experimental 30
7.1. Methodology 30
7.1.1. Portable X-Ray Fluorescence (pXRF) 31
7.1.2. Optical and Digital Microscopy 32
7.1.3. Thermally Assisted Hydrolysis and Methylation Gas Chromatography-Mass Spectrometry (THM GC-MS) 34
7.1.4. Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX) 35
7. 2. Results 36
7.2.1. Portable X-Ray Fluorescence (pXRF) 36
7.2.2. Optical and Digital Microscopy 37
7.2.3. Thermally Assisted Hydrolysis and Methylation Gas Chromatography-Mass Spectrometry (THM GC-MS) 44
7.2.4. Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX) 48
8. Discussion 52
8.1. Substrate 54
8.2. Lacquer and Ground 54
8.2.1. Lacquer Structure and Components 54
8.2.2. Ground Structure and Components 57
8.2.3. Adhesion between Substrate and Ground 58
8.3. Deterioration 61
9. Conclusion 64
10. Acknowledgments 66
Appendix I – Research Questions 76
Appendix II – Images 77
Appendix III – Archival Results 139
Appendix IV – Iconography and Composition of Decoration 146
Appendix V – pXRF 149
Appendix VI – Microscopy 150
Appendix VII – THM GC-MS 163
Appendix VIII – SEM-EDX 176
Appendix IX – Preservation Guidelines 195
All other translations, images and line drawings by the author unless stated otherwise.
Cover image: close up of lacquer decoration on the inside showcasing the problems discussed Photograph: Julia Wagner (iPhone 6plus).
1. INTRODUCTION
Written for a Master in Conservation and Restoration of Cultural Heritage at the University of Amsterdam (UvA), this thesis aims to investigate a diagnostic issue, specifically the deterioration of lacquer decoration on the porcelain bowl of a nineteenth century Japanese offering dish (inventory number DP240) from Huis ten Bosch Palace (HtB), part of the Royal Collection (Koninklijke Verzamelingen, KV), on permanent loan at Het Loo Palace (Paleis Het Loo, PHL).
The object consists of four parts, further described in chapter 2, however, the focus of this research was the deterioration of the lacquer decoration on the porcelain bowl. The primary problem under investigation was the lifting and detachment of the black lacquer layers from the porcelain substrate, particularly on the inside of the bowl.1 The main research question is: How far is the variation in the degradation of the lacquer layer on the porcelain bowl of the Japanese offering dish from Huis Ten Bosch Palace caused by differences in its composition and/or application technique? (see appendix I full list of research questions)
In order to understand the deterioration of the lacquer on this object, it is essential to find out as much as possible about the composition, layer structure and production technique together with the location and conditions in which the object has been kept. Investigation into the object’s origin, i.e. identifying whether the lacquer is European or Asian is one aspect of this research, building a knowledge base in regard to the object’s material characteristics that contributes to its conservation. In the long-term, the object will be conserved/restored and possibly exhibited, making this research a necessary step before decisions regarding treatment options can be made. The focus of this research into the production and deterioration of nineteenth century lacquer on porcelain provides an important contribution to existing literature on lacquer technique, as very little research has been undertaken on lacquer on porcelain (as opposed to wood) and to date nothing has been found on nineteenth century lacquered porcelain.
2. THE OBJECT 2.1. DESCRIPTION
The object DP240 described as “Japanese offering dish” or offerschaal from Huis ten Bosch (referred to from here on as HtB object or bowl) is a lidded vessel of hyperboloid shape with a truncated cone-shaped base on an octagonal pedestal. (App II: Fig. 1-3) It is made from mixed materials and consists of four parts:
• Octagonal wooden pedestal. Measurements: 41cm (height) x 80 cm (width)
• Bottom half of the vessel: lacquered wooden structure decorated with 12 oval porcelain
plaques.
• Top half of the vessel (Fig. 2.1; App II: Fig. 4-12), a blue and white porcelain bowl with
lacquer decoration in black, yellow, red, gold and grey. Measurements: 30cm (height) x 82cm (diameter)
• Lid (App II: Fig. 3) possibly lacquered wood decorated with a porcelain bird (App II: Fig.
3, 13)
Fig. 2.1. Porcelain bowl of the Japanese offering dish, inventory #DP240 (KV/PHL). Photograph: Julia Wagner
30 cm
41 cm 81 cm 82 cm
2.2. CONDITION Porcelain
Cracks:
• A large crack in the wall of the porcelain bowl from rim to base. (Fig. 2.2; App II: Fig. 4-6,
12, 14)
• At least one hairline crack, there may be more underneath the lacquer. (Fig. 2.2; App II:
Fig. 6, 14, 15, 18) Lacquer
Dulling: Some areas on the HtB bowl are glossier, the more deteriorated parts such as the inside is dullest. The areas that were covered, such as the base of the bowl, still show the original sheen. (App II: Fig. 18)
Lifting/detachment:
• Detachment of lacquer layers from adjacent lacquer layer. (App II: Fig. 19)
• Detachment of the lacquer decoration edges from the substrate, exposing a browned
adhesive in some areas (App II: Fig. 20) which is not fluorescent in UV. (App II: Fig. 21-24)
Cracks: predominantly along lacquer decoration edges (Fig. 2.2; App II: Fig. 4-5, 11, 14, 17) but also some on the inside base of the bowl. (Fig. 2.2; App II: Fig. 14, 25)
Lacunae: particularly on the upper half of the inside wall and spout (Fig. 2.2; App II: Fig. 11, 14) but also on one lacquer window on the outside (Fig. 2.2; App II: Fig. 4-5, 11, 17), along the base (App II: Fig. 6, 15) and spout. (App II: Fig. 6-8, 15-16)
Chipping: mostly around the rim and base. (Fig. 2.2: App II; Fig. 4-12, 14-18, 25) Abrasion: primarily along the rim and outside base. (Fig. 2.2; App II: Fig. 4-12, 14-18) Previous Restorations
• Discoloured retouching on lacquer and porcelain. (App II: Fig. 4-5, 12, 21, 23-24) • Filling of the large crack in the porcelain. (App II: Fig. 25)
• Consolidation of crack in the porcelain. (App II: Fig. 21-22)
• Possibly consolidation of lacquer decoration edges. (App II: Fig. 21-24)
Overall, the lacquer is in better condition on the outside of the bowl, hardly showing any cracking or lifting (Fig. 2.2; App II: Fig. 5-12, 15-16) with the exception of some missing areas on the edge of the lacquer decoration on one of the three porcelain windows (with the faded label, App II: Fig. 11, 17). The location of the different issues described above can be seen on the condition map (Fig. 2.2), which also puts the damage into context of likely direction (not distance) of light and heat sources in storage (as will be discussed in chapter 2.3, 6, 8). See App II: Fig. 14-17 for large scale condition maps of each separate area.
Fig. 2.2. Damage overview. Direction of possible light and heat sources shown at page edges. Porcelain bowl of the Japanese offering dish, #DP240 (KV/PHL). For detailed mapping see App II: Fig. 14-17. Photographer: Julia Wagner
Wi n d o w s a t th e J a p a n e s e r o o m i n H u is t e n B o s c h ( s o u th w e s t) Wi n d o w s ( St o ra g e ) He at e r (S to rag e )
Lacunae (through to porcelain/missing lacquer completely) Chipping (through to ground)
Abrasion (of surface decoration)
Lifting (of complete lacquer layer) Cracks (in lacquer and maybe porcelain)
Cracks (in lacquer)
2.3. BACKGROUND Provenance
Very little is known about the object’s provenance and whether its elements may have been altered, a question that arises when comparing the different style and material of the top and bottom (App II: Fig. 2-4). It is believed to have been made between 1850-1900 and was the centrepiece of the Japanese room (Japanse Zaal) room in Huis ten Bosch Palace. Earliest images showing it are dated 1899 (App II: Fig. 26) and 1900 (App II: Fig. 27) respectively. The exact date that it was removed from Huis ten Bosch and put into storage at Het Loo Palace is unknown but believed to be between after 1950s and before the 1960s.
It is yet to be confirmed when and how the object came to be in Huis ten Bosch Palace. It is possible that it was purchased in The Hague from the Japansch Winkel/Magazijn (1825-1843) or later Grand Bazar Royal (1843-1927) 2, a store mentioned as source for Japanese furniture for Huis ten Bosch Palace during the nineteenth century3. The store’s owner, Dirk Boer (1803-1877), who became Hofleverancier in 1837, 4 was known internationally for his trade but also exhibitions about Japan5, which was closed to Western countries aside Dutch traders from the 1630s until 18536. It is believed that some of the objects sold in the store came from Dutch traders as Boer established a wide trading network7 and wealthy clientele with some purchases by the Royal Cabinet of Curiosities (Koninklijke Cabinet van Zeldzaamheden) between 1828-31.8 Several purchases by Willem II are noted from 1835 onwards, with an increase of purchases noted from 1843.9 Other members who purchased from the store between 1840-1886 are princess Sophie and Willem III, among them a large Japanese vase (“een groote Japanse vaas” in 1845 by Willem II) and a Japanese bowl with a gilt base (“een rijk japansche coupe op vergulden voet” in 1863 by Willem III). (App II: Fig. 28)
Prints from 1850 and photographs from around 1910 depicting the inside of the shop provide some examples of the type of items sold. (App II: Fig. 29-32) Although none illustrate a similar object, it shows the diversity available at the time and that porcelain was a major part of the inventory. However, lacquerware is also seen in the 1830s as its popularity grew through its presence in the Royal Cabinet of Curiosities.10 While lacquerware was known since the beginning of the 17th century, it was owned mostly by the elite.11 It should be noted that lacquer wares sold at the Grand Bazar also included imitation lacquers.12
The royal family may have also acquired it elsewhere such as from the world exposition that took place in Amsterdam in 1883, (chapter 4 elaborates on the importance of these fairs for the promotion of Japanese arts and crafts). (App II: Fig. 33) Given the size of the object, it may also have been a diplomatic gift.13 The exact circumstances of acquisition still need to be confirmed through further archival research.
2
Keblusek, Japansch Magazijn, 18-26. 3 Rem, Hofmeubilair, 20.
4
Keblusek, Japansch Magazijn, 24-26. 5
Baird and Backx-Palsgraaf, "Viewing Japan and China,” 1. 6
Kobayashi-Sato, “An Assimilation,”165; Keblusek, Japansch Magazijn, 7; Laver, The Sakoku Edicts, 16, 175.
7
Keblusek, Japansch Magazijn, 19-21. 8 Keblusek, Japansch Magazijn, 24-26. 9
Keblusek, Japansch Magazijn, 24-26. 10
Keblusek, Japansch Magazijn, 22. 11 Keblusek, Japansch Magazijn, 22.
The Japanese Room
The bowl is known to have been displayed in the Japanese room at Huis ten Bosch palace from at least 1898. Illustrations and photographs from the Japanese room at Huis ten Bosch (App II: Fig. 26-27, 34-53 for a selection and a complete list in appendix III) give insight into the history of the object at Huis ten Bosch, and further some understanding of the condition of the lacquer today. (Table 1-2)
Table1. Information deducted from archival research
Observations from photographs Date
- Object in the Japanese room at Huis ten Bosch - Room without the object
1898 until 1950 (or longer) 1936 and 1956
- Lid with porcelain bird on the bowl - Position: in the centre of the room
- Position: spout pointing into opposite direction14 - Gloss15
- Lacunae
o On spout
o On outside lacquer window - Restorations?
o Spout lacunae appears smaller16
o Current brush stroke on spout not on object o Crack in bowl and retouching
- Sticker/paper label on outside window17
1900 and 1905 (only!) Whenever pictured 1905 and 1950 Until 1937 (or longer) 1900
1905
Between 1900-1914 1947
1950 (maybe 190518) After 1914 (or later)
Table 2. Evidence of use of Huis ten Bosch palace and the Japanese room
Date Use
End 1700s Japanese room (facing south-west, Fig. 2.2, App II: Fig. 54) was converted from a bed chamber to an audience room in style of the Far East.19
1815 - 1940 From the proclamation of King Willem I (1815) the Palace was regularly inhabited by members of the royal family. King Willem I used the palace. Later it was inhabited during summer by Queen Sophie, the first wife of King William III. Later Queen Wilhelmina used it as a summer residence during the First World War and before moving to England due to the German invasion in 1940.20
1877 - 1899 Palace was only occasionally in use.21
14
Spout position appears often slightly different, but it is difficult to compare with the different camera perspectives. This may be an explanation for the abrasion near outside base and possibly also other damage occurring during handling along the rim.
15
There may have been attempts to restore shine as it was common during cleaning routines (chapter 6, 8), however, comparing the object’s matt surface with previous images there is a difference in shine (Fig. 2.1, App II: Fig. 48)
16
Very tentative observation due to low image quality 17
The frame of the faded label resembles the frame used by the royal family. (App II: Fig. 55) The images from the 1940s and 50s do not show the lacquer window with the stamp to confirm whether it was already there at the time.
18
Very tentative observation due to low image quality 19 Ex, The Brocadian Paradise, 11.
20
Ministerie Van Algemene Zaken, "Geschiedenis Paleis Huis Ten Bosch." 21 Wander, Haagse Huizen, 41.
1899 The first international peace conference in 1899 took place in Huis ten Bosch22, with the main conference room being set in the Oranje Zaal adjacent to the Japanese room. It is possible that the other rooms were used as smaller meeting rooms as in the case of the Witte Zaal meaning furniture may have been moved to accommodate conference tables. (App. II: Fig. 56-57)
1940 - 1945 Huis ten Bosch was severely damaged during the Second World War and uninhabitable after the liberation. The art treasures were brought to safety in time, but walls, ceilings and floors were damaged by bullets, shrapnel and bomb fragments.23
1950 - 1956 Restoration of palace24, during which no substantial changes were made25, however the carpet previously in the Witte Zaal was moved to the Japanse Zaal (App. II: Fig.50, 52).
To date, no images of the object in the palace after 1950 were found and a staff member who started working there in the 1960s confirmed they had never seen the object26. This date coincides with a major restoration of the palace in the 1950s. An indication of a possible reason for the object’s removal during this restoration was a comment with regard to the renovations that “in the course of the centuries - as in every inhabited house - more and more had been added and relatively little removed. So, it is possible that in 1938 a room, intended as a living room, would have housed seventeen large decorative vases, some more than a metre high, making the room look more like a storage than living room.”27
It is unlikely that renovations are the reason for the object’s absence in 1936 due to this being a time of unrest when the Great Depression hit the Netherlands between 1933-193628. An image dated 1937 shows the object back in the room, yet, the description of the room by E. C. Houbolt published in 1939 does not mention it, while the lacquer cabinets, porcelain and tapestry find mention29, which seems unusual given its central position and unique appearance.30
3. PREVIOUS RESEARCH AND AVAILABLE SOURCES
Art historical and technological context, knowledge about Japanese and European lacquer as well as the object’s background were explored through secondary literature. Much has been written about lacquer on wood, for instance Marianne Webb’s31 Lacquer: Technology and Conservation and Shayne Rivers’32 (et. al.) East Asian Lacquer: Material Culture, Science and Conservation were among the sources consulted for an understanding of lacquer technique, properties and deterioration. The former particularly useful as information regarding technique always refers to implications for deterioration and conservation, while the latter as a 22
Mostard, Den Haag, Oranje Residentie, 147-148. 23
Ministerie Van Algemene Zaken, "Geschiedenis Paleis Huis Ten Bosch." 24 Wander, Haagse Huizen, 43.
25
Loonstra, Het huys int bosch, 151. 26
Personal communication with Liesbeth Schotsman, 12-12-2018. 27
Schenk, and Spaan. Huis ten Bosch, 88. 28
Beishuizen, and Werkman, De magere jaren, 10, 235. 29
Houbolt, Het Huis ten Bosch, 52-55.
30 Chapter 4 and appendix IV shall explore how such a unique object may not be unusual given the art historical and socio-political context.
31
Specialising in the conservation and restoration of Asian and western lacquers.
compilation of articles by conservators and conservation scientists provides insight into lacquer analysis and deterioration. Günther Heckmann’s33 Urushi no Waza aided in getting an impression of traditional tools and a large variety of materials and techniques used and how these changed over centuries.
Due to discrepancies encountered in Western literature particularly regarding terminology34, it was attempted to restrict cited information to Japanese sources and discuss variations with lacquer specialists. Due to the fact that lacquered porcelain is not commonly found in Japanese collections35, being an export product, no Japanese literature regarding the technique of lacquering porcelain36, so-called Toutai37, exists. Some Japanese literature was consulted, to confirm information obtained from German, English and Dutch sources, particularly for the definition of different types of lacquer and ingredients used. Some literature specifically addressing the production, deterioration and conservation of lacquered porcelain such as Suzanne Lambooy’s “Japans porselein met ‘urushi’-lakdecoraties” (Afstudeeronderzoek, Instituut Collectie Nederland, 2003) which investigated the lacquer with microscopy of cross-sections Py-GC-MS, FTIR and SEM-EDX. Tania Korntheuer-Wardak’s “Nichtkeramische Reliefapplikationen auf japanischen Imari- Vasen” (Seminararbeit, Hochschule für Bildende Künste Dresden, 2000). The latter is particularly relevant in terms of production technique due to the relief structure38, investigated with microscopy, UV photography, FTIR, Optical Emission Spectroscopy (OES) and microchemical analysis [sic!]. Some of the results of these works will be addressed in chapter 5-6 and compared with findings in chapter 8. While literature regarding lacquered porcelain from the early 1700s was available, information regarding nineteenth century lacquered porcelain or porcelain objects lacquered on the interior was not found.39
Archival research at the Royal Archives (Koninklijke Verzameling), the image databases of municipality archive of The Hague (Haags Gemeentearchief), the Dutch Cultural Heritage Agency (Rijksdienst voor het Cultureel Erfgoed) and the Dutch National Archives (Nationaalarchief) was conducted to investigate how the object may have been acquired by the Dutch royal family but also to shed some light on part of its history at Huis ten Bosch Palace and in what conditions it may have been displayed and stored. Whereas art-historical, scientific and conservation experts in this field were consulted to provide insight into the context and the common problems of lacquerware on porcelain.
4. ART-HISTORICAL CONTEXT
The first evidence of lacquer decoration on ceramics is found on archaeological finds from the Neolithic period in the Liang-chu culture (3300-2300 B.C) from the Yangtse delta in China.40 Lacquer on blue and white porcelain existed in China during the Ming period (1368–1644), however, it did not occur frequently, possibly due to the high status of each of the techniques
33 Private conservator and specialist on Japanese lacquer work. 34
Personal communication, Dave van Gompel, 10-06-2019. 35
With exceptions such as the Kyushu Ceramics museum for example. 36
Personal communication, Yamashita Yoshihiko (independent lacquer conservation specialist from Tokyo, known for his collaboration in projects such as the Mazarin chest of the Victoria & Albert Museum in London, or the lacquered vases from the Dresden porcelain collection), 10-05-2019.
37 Personal communication Dave van Gompel, 06-05-2019. 38
While decoration techniques on the HtB bowl are not as elaborate as on the vases from Dresden, there is some low relief on the outside of the bowl (appendix IV).
39 Reading list of lacquer literature (Victoria & Albert Museum):
http://www.vam.ac.uk/content/articles/l/lacquer-reading-list/. 40 Kopplin, “’So schwarz wie Lack‘,“ 12.
on their own.41 Well before the nineteenth century, porcelain and lacquerware were traded between Asia and Europe, and between Japan and the Netherlands from the beginning of the seventeenth century.42 Wares were often made specifically for export and therefore adapted to suit the European use regarding shape, taste and imagination of the East regarding decoration. 43 This meant a combination of various patterns and shapes from different regions.44 Moreover, the popularity of oriental lacquer led to its imitation within Europe45 which is another factor that can pose a challenge when trying to discern the origin of such objects. A Chinese blue and white porcelain vessel with lacquer decoration in the British museum is a rare exception and seen as a technological predecessor for lacquered porcelain in the seventeenth century (as will be elaborated later).46 Its shape was inspired by bronze zun vessels and may be what inspired the shape of the HtB object. As zun vessels were ritual vessels, this may explain the name of the object as Japanse offerschaal. Looking at the porcelain bowl on its own, it also resembles gu vessels, on which the design of the famous beaker vases known in garniture sets was based.47 (App II: Fig. 58) A revival of lacquer on ceramics appeared at the end of the seventeenth century in China, in form of laque burgautée, lacquered porcelain with mother of pearl inlays.48
As the combination of lacquer on porcelain in Japan was specifically made for the export market49, not many pieces exist in Japanese collections.50 Lacquered porcelain was particularly popular with the German, Dutch and British markets towards the end of the seventeenth century, combining two of the most popular luxury items at the time.51 The most famous examples of lacquered porcelain in European collections are the over sixty pieces in the Dresden porcelain collection, commissioned around 1700.52 Of these particularly the birdcage vases strike some resemblance due to their wide, open rim. (App II, Fig. 59)
Some examples of lacquered porcelain in other Western collections are shown in App II: Fig. 59-60, although, not many are from the nineteenth century. When looking at other examples of lacquered porcelain, it seems that this object is quite unique, however, despite this, it could be described as typical for the nineteenth century as encountered on world fairs with a huge variety in shape and styles. (App II: Fig. 61-63) Similarly, the range of styles regarding lacquerware (practised alongside traditional ones) increased during the nineteenth century.53 Iconography and Composition of Decoration
The iconography can provide clues regarding dating and/or origin. There are similarities between the HtB bowl and the Japanese Dresden birdcage vases dating from ca. 1700, through the underglaze blue decoration positioned on the inside of the rim in form of dragons, which in case of the birdcage vases are chasing a pearl54. The dragon motif is traditional and still in 41
Kopplin, “’So schwarz wie Lack‘,“ 17-18. 42
Impey, “A Brief Account,” 15. 43 Hidaka, “Foreign Taste,” 31-46. 44
Hidaka, “Foreign Taste,” 31-46. 45
Hidaka, “Foreign Taste,” 31-46. 46
Kopplin, “’So schwarz wie Lack‘,“ 18. 47
Ströber, “Chinesische und japanische Porzellane,” 28. 48
Kopplin, “’So schwarz wie Lack‘,“ 21-22. 49 Heckmann, Urushi no waza, 65-66. 50
Korntheuer-Wardak "Nichtkeramische,“ 4, 12. 51
Ströber, “Chinesische und japanische Porzellane,” 27-28. 52 Espir, European Decoration, 48-49.
use today, yet the distinctive design of the lotus flower55 on the outside of the bowl (especially the centre)56 suggests this is from the nineteenth century. For more information about the iconography seen on the bowl see appendix IV. Awareness in Europe of these typically Japanese elements is shown in pattern books therefore their presence alone cannot exclude that the object may have been japanned or lacquered in Europe. (App II: Fig. 64, appendix IV) What makes the object seem to stand out is the different porcelain elements seem to come from different workshops, such as Arita (bowl) and Seto (porcelain plaques).57 Given the assumed production date is late nineteenth century, this may not be so unusual due to increased collaboration between workshops, involvement of foreign expertise in production technique and promotion of Japanese arts and crafts in world fairs, which allowed for a wide range of styles between tradition and innovation.58 (Appendix IV)
5. MATERIALS AND PRODUCTION OF PORCELAIN AND LACQUER 5.1. PORCELAIN
Hard paste or ‘true’ porcelain is a hard white ceramic of crystalline structure that was first produced in China in the 9th - 10th centuries, in Japan in the early 17th century and in Europe during the early 18th century.59 It is made from kaolinite clay and petuntse (or touseki in Japan)60, a rock comprising mica, feldspar (a crystalline mineral from aluminium silicates ) and quartz (or silica dioxide). 61
Typically, porcelain is coated with a glaze, which has a chemical composition that is compatible with the paste, such as silica in combination with an alkali (lime or potash) for hard paste glazes, while soft paste glazes are based on silica with lead oxide.62 Decoration can be applied as underglaze, in-glaze or on-glaze decoration and gilding. Metal oxides are used as in-glaze colourants, cobalt oxide being used for blue. The resulting colour for most depends on the type of glaze to which it is applied, and, to some extent, whether the firing conditions are oxygen-rich or reduced.63 Table 3. gives an overview of the colours achieved in different atmospheres by different oxides64 and serves as a reference for oxides detected in the HtB bowl underglaze blue.
Table 3. Colour development from adding colourants to glazes
Colourant Oxidising Atmosphere Reducing Atmosphere
Iron Tan, yellow, brown, green with copper Grey, blue, green (celadon), red
Cobalt Blue Blue
Manganese Purple, purplish blue, black Brown
Nickel Grey or brown Grey or grey-brown
Chromium Green Yellow, turquoise with cobalt
55
Personal communication, Tomoko Fujiwara, 30-05-2019. 56
Personal communication, Ink de Pree, 14-06-2019. 57
Personal communication, Tomoko Fujiwara, 30-05-2019. 58
Jahn, Meiji Ceramics, 15-19, 32-37. 59
Rice, Pottery Analysis, 6.
60 Wilson, Inside Japanese ceramics, 43. 61
Analytical Methods Committee, "X-ray fluorescence,” 2371; Rice, Pottery Analysis, 45; Arts, Japanese porcelain, 27-28.
62 Analytical Methods Committee, "X-ray fluorescence,” 2371. 63
Analytical Methods Committee, "X-ray fluorescence,” 2371. 64 Rice, Pottery Analysis, 337.
The Production of Porcelain in Japan
In Hizen (Japan) white porcelain stone (Amakusa stone) was found underneath feldspathic rock and, as opposed to the artificial mixture of porcelain in China, it contained the correct ratio of kaolin, quartz and feldspar (30:45:25)65 to make hard porcelain. As an exhibition catalogue from the world fair in Philadelphia at 1876 elaborates, the porcelain stone was pulverised after excavation, mixed and washed66 and while in early production it was used without any additions or adjustments67, additions were made during the nineteenth century68. In early production, the comparatively high percentage of quartz is responsible for its plasticity as a raw material but also its rigidity during firing, especially given the lower ratio of feldspar.69 The ability to make large porcelain pieces is said to have improved in Japan from about 1800 onwards, when saggars came into use, so the previous difficulties may not have derived from the porcelain composition but may have been more related to the ability to evenly distribute and control the kiln temperature.70 Although, naturally components in the porcelain clay mixture may not have been distributed evenly, which could have been another reason for distortion and uneven shrinkage i.e. when feldspar is distributed unevenly.71 The size of the HtB bowl, may be an indication of its production in the nineteenth century rather than earlier.
As opposed to Chinese porcelain, in Japan blue and white ware was fired twice, first at 700°C, after which is was decorated, glazed before being again fired at a high temperature (about 1350°C). 72 The act of painting in between these firings, means in general the brush strokes can be slightly blurred73, as seen in the HtB bowl (App II: Fig. 65). Underglaze blue (or gosu) contains cobalt, manganese and iron.74 As a result of the influence by Gottfried Wagener75, during the nineteenth century (especially after 1885/86) it was common for Japanese potters to use imported, chemically produced cobalt oxide from Europe and America76, which was much purer than native or Chinese gosu and easier to use, but much harsher in tone77. In some workshops such as the one of Makuzu Kouzan, its colour was approximated to the colour of gosu by the addition of iron, manganese or nickel.78 It was also common to experiment with different tones.79 A master potter from a Seto workshop was said to have been skilled in making underglaze blue with iron and chrome.80
In early days of Japanese porcelain production (the seventeenth century) in Japan wares were glazed with ash-containing materials, and later feldspar and lime, before being fired a second time in a sloped kiln built as introduced from Korea.81 The reducing atmosphere in these kilns was responsible for the iron in the glaze giving it a green tinge.82 This is particular for early
65
Arts, Japanese porcelain, 28-29. 66
Impey, The early porcelain kilns, 34. 67
Arts, Japanese porcelain, 28-29.
68 Impey, The early porcelain kilns, 34; Ross, "Late Nineteenth," 4; Yoshie “Export porcelain,” 12, 80, 91. 69
Arts, Japanese porcelain, 28-29. 70
Arts, Japanese porcelain, 29-30. 71 Arts, Japanese porcelain, 29-30. 72
Arts, Japanese porcelain, 30-31. 73
Arts, Japanese porcelain, 30-31. 74
Arts, Japanese porcelain, 30-31. 75
German scientist who introduced coal and gas kilns. Source: Yoshie, “Export porcelain,” 31-33. 76
Ross, "Late Nineteenth," 4-5. 77 Pollard, Master Potter, 72. 78
Pollard, Master Potter, 72. 79
Pollard, Master Potter, 72. 80 Yoshie “Export porcelain,” 27.
Japanese ceramics and not observed on the HtB bowl. One characteristic of Japanese glaze that can be observed in the object, is small pinholes in minute depression, so called muslin. (App II: Fig. 65)83
Spur marks in the glaze on the base, which arise from supporting ceramics in the kiln84, are more common at the back of large pieces85. Otherwise, (especially smaller) pieces may have rested in sand, of which reddish remnants are visible along the base, or in case of larger pieces ceramic pillars may have been used.86 Spur marks seldom occur in later nineteenth century pieces but it is not always possible to use the presence or absence of marks for dating.87 The base of the HtB bowl is covered with lacquer (App II: Fig. 18), however, reddish traces88 can be seen through damaged lacquer areas along the base edge. which is an indication it may be nineteenth century89. (App II: Fig. 25)
The Production of Porcelain in Europe
Hard-paste porcelain was first produced in Europe (Dresden, Germany) in 170890 and produced by mid 18th century throughout Europe91. A comparison of different ratios of components in nineteenth century porcelain by Arts shows that Japanese porcelain may consist of a higher percentage of quartz +45%, whereas Chinese 30% and European under 25%.92 However, Europeans imitations of Japanese had the same high quarts percentage.
5.2. LACQUER AND GROUND CONSTITUENTS 5.2.1. JAPAN
While the components and structure of lacquer decoration are introduced below, it was not possible within the scope of this thesis to address the great variety of techniques, given lacquering has been practised in Japan for millennia93.
Lacquer Constituents
Urushi (or Japanese lacquer) can be described as a natural polymer that is remarkably resistant to water, acid, and to a certain extent, heat.94 It is derived from the sap of several species of trees within the Anacardiaceae family, of which rhus verniciflua is said to be most suitable due
83
Arts, Japanese porcelain, 30-31. 84 Rice, Pottery Analysis, 482. 85
Arts, Japanese porcelain, 32. 86
Arts, Japanese porcelain, 32-33. 87
Arts, Japanese porcelain, 33. 88
The unglazed porcelain and/or the kiln-sand that remains on the bottom after firing with a high iron content will turn pink/red in oxidising firing conditions.
89 Personal communication, Tomoko Fujiwara (Kyushu Ceramic Museum), 30-05-2019. 90
Rice, Pottery Analysis, 19. 91
Buys and Oakley, Conservation and Restoration, 15. 92 Arts, Japanese porcelain, 29.
93
Lambooy, "Japans porselein met ‘urushi’,” 41. 94Asian Urushi Project, "Asian Lacquer Craft Exchange,"
to the comparatively low amount of impurities.95 Urushiol is the active ingredient that causes its polymerisation96 (Fig. 5.1) in conjunction with laccase97.
Together with the age of the tree98, the harvesting time and refinement process99 is an important factor for the water content, category, quality and use of the lacquer100 from coatings of everyday items to entire temples101. The main collection time is June until September. 102 Table 4 illustrates the average composition of the raw lacquer.103 For information on curing process see chapter 6, App II: Fig. 66-67.
Table 4. Average components of raw lacquer (ki urushi) Percentage Components
60-65% Urushiol
20-30% Water
10% Water-soluble plant gum
Mono-, oligo and polysaccharides Water-insoluble glycoproteins
Enzymes: peroxidase, stellacyaninin, Rhus laccase
The refinement process to make the actual coating material, consists of reducing the water content. 104 Oils, resins or colouring agents may be added to achieve the type of lacquer needed.105 Traditionally coloured lacquer was pigmented by the lacquer artists themselves, while the various forms of black lacquer would have been made by the manufacturers.106 Table 5 is comprised of a list of different types of urushi and their refinement process that may have been used, based on a glossary by Hiroshi Kato, Sadatoshi Miura and Michiko Matsubara. Nomenclature regarding lacquer types may vary in different schools/regions and discrepancies in Western literature are often found. Nevertheless, some more examples of different lacquer types can be found in Webb’s Lacquer Technology and Conservation and Heckmann’s Urushi no Waza who summarises lacquer types from the Greater Tokyo area, the former Edo school of lacquer.107
95
Webb, Lacquer, 4. 96
Webb, Lacquer, 3-4, 9. 97 Drescher, Kintsugi Technik, 20. 98
Piert-Borgers, Restaurieren mit Urushi, 1. 99
Piert-Borgers, Restaurieren mit Urushi, 1. 100
Drescher, Kintsugi Technik, 19-24. 101
Heckmann, Urushi no waza, 15. 102
Heckmann, Urushi no waza, 14.
103 Niimura and Miyakoshi, “Identification of Oriental Lacquer,” 123-124; and Weintraub et al. "Urushi and conservation," 41.
104
Heckmann, Urushi no waza, 16. 105 Heckmann, Urushi no waza, 16.
Fig. 5.1. Urushiol. While rushiol is the active ingredient in China, Korea and Japan, it is laccol in Vietnam and Thailand, or thitsiol in Thailand and Burma that causes polymerisation of lacquer Sources: Webb, Lacquer, 8-9.
Table 5. A selection of types of lacquer Type Description & Preparation
Ki-urushi Raw lacquer straight from the lacquer tree.108 The initially milky white substance browns within minutes when exposed to air.109 (App II: Fig. 66) There are different subcategories depending on harvesting time: hatsugama (June-July), sakari (August-October), eda urushi (November and onto winter months from branches). 110 Hatsugama urushi, being high in water content and very adhesive, it is often used to make suri urushi for adhering gold powder or for shining.111Sakari urushi is often used to make transparent and black lacquer. While in the past eda urushi may have been used for ground layers, nowadays Chinese urushi may be used for these.
Suki urushi Translucent lacquer: made from ki-urushi by reducing the water content by gentle heating112 (kurome) or under stirring (nayashi)113 for about 1-2 hours to reduce the water content to 2-3% and is carefully controlled to maintain the enzymes, as otherwise the hardening process would be hindered.114
Kuro urushi Black lacquer: made from translucent lacquer blackened with carbon black (lampblack/soot) and/or iron hydroxide115 (iron oxide tarnished in rice vinegar)116. Aka urushi Red lacquer: made from translucent lacquer and coloured with either: Cinnabar
(mercuric sulphide, HgS)117 or cadmium red (cadmium silfide, CdS, cadmium selenide, or cadmium sulphide selenide)118. Both types referred to as shu urushi and may be mixed to achieve the desired tone.119 Alternatively, translucent lacquer may be coloured with red iron oxide (a red earth pigment, Fe2O3)120resulting in a slightly browner tone, bengara urushi 121.
(App II: Fig. 66) Ki iro
urushi
Yellow lacquer: is also made from translucent lacquer and coloured with either: Auripigment (or orpiment, AS2S2)122 is an artificial mineral pigment and natural arsenic blend and used in Japan from the second half of the seventeenth century. Cadmium yellow, cadmium sulfide (CdS) first produced in 1817123 or chromium yellow, lead sulfate (PbSO4) discovered in 1809124.
Traditionally, lampblack, cinnabar and iron oxide were most commonly used pigments, whereas the colour range was enlarged widely during the late nineteenth century. 125 Commonly used oils that may have been added either during the refinement process or when colouring the lacquer are all plant-based: drying oils (yam or linseed126, sesame seed and princess trea127) and non-drying oils (rapeseed128). The presence of protein indicating the addition of
108 Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 593. 109
Drescher, Kintsugi Technik, 19. 110
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 593. 111
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 593. 112
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 598. 113
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 598.
114 Niimura and Miyakoshi, “Identification of Oriental Lacquer,” 123-124. 115
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 593-594. 116
Drescher, Kintsugi Technik, 23. 117 Heckmann, Urushi no waza, 33. 118
Eastaugh, Pigment Compendium, 76. 119
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 598. 120
Heckmann, Urushi no waza, 33. 121
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 588. 122
Heckmann, Urushi no waza, 34; and Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 600. 123 Heckmann, Urushi no waza, 34.
124
Heckmann, Urushi no waza, 36. 125
Webb, Lacquer, 8. 126 Webb, Lacquer, 7. 127
Heckmann, Urushi no waza, 16. 128 Heckmann, Urushi no waza, 16.
animal glue within lacquer layers, while being uncommon (as it dries very fast)129, was observed130 in some Japanese sources from the early nineteenth century, when it may have been used to adjust the lacquer to desired properties.131 For more information regarding the use of animal glue, see information about ground layers.
Ground Constituents
Lacquer layers are not directly applied to the substrate but to ground layers, which smoothens out imperfections in the substrate132 and act as a buffering zone for subsequent changes to the what is commonly a wooden substrate133. Ground can be comprised of many different materials; table 6 is a list of commonly found fillers and table 7 common binding media and table 8 urushi based adhesives.
Table 6. Common fillers used in and underneath ground layers Type Description & Preparation
Jinoko Coarse grind of baked earth134
, softer in comparison to tonoko. 135
Colour and constituents may vary depending on region and firing process.136 The famous clay from North-West of Honshū is very hard and fine.137 Moreover, due to its open pores, the particles interlink well when mixed with lacquer, resulting in great stability.138 The average composition of red clay: 66.1% silicon oxide, 17.7% aluminium oxide, 4.3% iron oxide, 0.2% calcium oxide and 11.7% of other constituents.139 Once milled, sieved and sun-dried, it is heated to 750°C for 5-6 hours then crushed to different grain sizes.140 There are two kinds of jinoko, clay-type (kneaded with water and ki-urushi), and diatom-type (mixed with nori urushi)141
Tonoko Finer and harder clay powder that is washed and not fired.142 It is usually mixed with urushi for use in ground layers or for polishing top lacquer layers (dozuri) when combined with oil.143
Gofun Ground shells, white coloured powder144
Ji Mixture of jinoko (coarse) and urushi. It is used for the bottom ground layer.145 Sabi Mixture of tonoko (fine) kneaded with water and then ki urushi. It is used as top ground
layer.146
Kiriko Mixture of ji and sabi (coarse and fine)for the middle ground layers.147
129
Personal communication, Dave van Gompel, 10-06-2016. 130
Py-GC-MS with derivatisation of the lacquer sample with tetramethylammonium hydroxide (TMAH) prior to analysis.
131
Heginbotham and Schilling, "New evidence," 102-103. 132
Webb, Lacquer, 25.
133 Heckmann, Urushi no waza, 82. 134
Webb, Lacquer, 25. 135
Heckmann, Urushi no waza, 83. 136 Webb, Lacquer, 25.
137
Heckmann, Urushi no waza, 83. 138
Heckmann, Urushi no waza, 83. 139
Heckmann, Urushi no waza, 83. 140
Heckmann, Urushi no waza, 83. 141
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 591. 142 Heckmann, Urushi no waza, 83.
143
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 599. 144
Lambooy, "Japans porselein met ‘urushi’," 44.
Table 7. Commonly used binding media in ground layers Type Description & Preparation
Ki urushi See table 5.
Nikawa Animal glue was commonly used to substitute the expensive urushi in the ground layers in export ware.148 While for earlier lacquerware this may have been fish glue, during the nineteenth century deer skin glue was commonly used.149 Cowhide is also often named as source for nikawa.150
Other urushi substitutes in export ware
Thai or Burmese lacquer (containing thitsiol)151, persimmon juice152, or resins such as gum benzoin153, or shellac154 were detected155 in seventeenth century Japanese export lacquerware156. Some of these materials were also commonly used in imitations lacquers (see section for European lacquers below) or for early restorations157.
Table 8. Urushi-based adhesives
Type Description & Preparation
Mugi urushi A strong adhesive made from ki urushi and flour kneaded with water, used for kanshitsu Buddha sculptures and nowadays used as adhesive for wood or for reassembling broken ceramics or wood.158
Nori urushi An adhesive from ki urushi and rice paste (cooked from very fine rice flour). It is used to adhere cloth but can also be used as binder for jinoko.159
Nikawa urushi An adhesive made from animal glue and raw lacquer is the strongest of the urushi adhesives and due to its resistance to water used to mend porcelain and glass.160 As opposed to mugi or nori urushi it is not commonly used in lacquerware for adhering the preparatory cloth (see Fig. 5.2 below)
Kokuso Sawdust and hemp fibres kneaded into mugi urushi. Often used as shape forming material to treat cracks on substrates or reproduce missing parts161 and level depressions prior to application of ground or strengthen corners of an object162.
148
Webb, Lacquer, 27.
149 Personal communication, Yamashita Yoshihiko, 10-05-2019. 150
Morita, "Nikawa-Traditional production of animal glue in Japan" 121-122. 151
Heginbotham and Schilling, "New evidence," 97-99. 152 Heginbotham and Schilling, "New evidence," 102. 153
Heginbotham and Schilling, "New evidence," 101. 154
Heginbotham and Schilling, "New evidence," 101-102. 155
Py-GC-MS with derivatisation of the lacquer sample with tetramethylammonium hydroxide (TMAH) prior to analysis.
156
Heginbotham and Schilling, "New evidence," 92-106. 157 Webb, Lacquer, 64.
158
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 594. 159
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 595. 160 Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 595. 161
Kato, Miura and Matsubara, “Glossary of Urushi Terms,” 593. 162 Webb, Lacquer, 26.
Analysis of Japanese Lacquered Porcelain in Dutch and German Collections
As elaborated in chapter 3, Korntheuer-Wardak investigated lacquered porcelain in the Dresden collection (with similar materials on sixty vases163), while Lambooy analysed two lacquered porcelain vases of the Rijksmuseum164, in both cases the objects were from the early 18th century.
The ground used for the decoration on the Dresden vases included quartz, aluminium, calcium, iron, protein binder and probably urushi (Japanese lacquer) in different proportions.165 Additionally, one type of ground used was composed of the same components except calcium, but including plant fibres.166 This ground was very fine and, observed under the microscope, appeared to be Japanese paper, kouzo.167 Moreover, an adhesive made from protein, calcium stereate and urushi was found. 168 Materials used for the lacquer and surface decoration included cinnabar, red iron oxide, lampblack, white lead, orpiment, indigo and gold dust in an oil binder.169 Ströber notes that in one of the lids of the Dresden vases, underneath the bottom ground layer, there was white adhesive consisting from minerals such as calcium carbonate with a protein binder.170 Additionally, plant-based fibres were worked into the adjacent ground layer, sealed off with a soot coloured coating.171
The binding medium of the ground in the lacquered porcelain from the Rijksmuseum was possibly a gum and, not urushi, animal glue or starch (however the exact material is unknown), while clay was used as a filler.172 The lacquer was pigmented with ivory black and included a drying oil, which most likely allowed application of thicker layers and prevented brushstrokes to be visible, therefore reducing manufacturing time.173
163
Korntheuer-Wardak, "Nichtkeramische,“ 215. (ZKK) 164
Lambooy, "Lacquer on Japanese porcelain,” 1076. 165 Korntheuer-Wardak, "Nichtkeramische,“ 220. (ZKK) 166 Korntheuer-Wardak, "Nichtkeramische,“ 220. (ZKK) 167 Korntheuer-Wardak, "Nichtkeramische,“ 102. 168 Korntheuer-Wardak, "Nichtkeramische,“ 220. (ZKK) 169 Korntheuer-Wardak, "Nichtkeramische,“ 219-221. (ZKK) 170
Ströber, “Chinesische und japanische Porzellane,” 30. 171 Ströber, “Chinesische und japanische Porzellane,” 30.
Structure of Lacquer and Ground Layers
Fig. 5.2. Schematic drawing (by the author) of the build-up of ground and lacquer layers on a wooden substrate as per Webb’s description in Lacquer Technology and Conservation. A cloth, usually hemp, cotton, linen or silk (and sometimes paper) on wooden substrates acts as reinforcement and preparatory step before application of ground layers.174 Each application of ground layer and lacquer layer is followed by dry sanding (ground layers), wet sanding (lacquer layers) and finally polishing.175 For this, different materials with different grades or grain sizes may be used, for instance, charcoal powder for the lacquer layers or tonoko for the final layer.176
The pictured method (Fig. 5.2) is the one used for high quality lacquerware, honkataji method, whereas honji, is the same process but simplified by fewer layers.177 This is often the case for export ware due to the high demand for lacquerware that arose in nineteenth century world fairs addressed earlier. which led to mass production of items of medium to moderate quality on the one hand and also the use of substitute materials, but on the other hand there were objects of high quality made using traditional materials and procedures.178
While the application of lacquer on wood and the preparation of the wooden substrate is described in literature, porcelain is often merely named as another common substrate without elaborating on the difference in techniques used on porous and non-porous substrates.179 In general the build-up of layers follows the same principles, however, occasionally ground layers on metal substrates are omitted as these would weaken the bond between the lacquer and substrate180 also heat is involved, depending on the type of metal181. This indicates that application methods were adapted.
174
Heckmann, Urushi no waza, 68. 175
Heckmann, Urushi no waza, 84. 176 Heckmann, Urushi no waza, 84. 177
Webb, Lacquer, 28. 178
Heckmann, Urushi no waza, 284. 179 Webb, Lacquer, 23.
180
Webb, Lacquer, 119,120.
The Structure of Japanese Lacquered Porcelain in Dutch and German Collections
Korntheuer-Wardak investigated lacquered porcelain in the Dresden collection (with similar materials on sixty vases182), while Suzanne Lambooy observed the structure on the lacquered porcelain vases of the Rijksmuseum183, in both cases objects are from the early 18th century. (Fig. 5.3-5.4).
Fig. 5.3. Schematic drawing on structure of substrate and layers between ground and substrate. In Type A areas of porcelain that were intended to be covered with lacquer were glazed but then sanded down before the application of ground layers184, as is the case with some of the lacquered porcelain in the Dresden collection. This group of objects may have been originally intended to be decorated with enamel colours.185 The variant of Type A represents modern Toutai (lacquering of porcelain), the same technique as in Type A but without the use of fibrous material, such as hemp cloth or paper. 186 (App II: Fig. 68)
182
Korntheuer-Wardak, "Nichtkeramische,“ 215. (ZKK) 183
Lambooy, "Lacquer on Japanese porcelain," 1076. 184 Korntheuer-Wardak, "Nichtkeramische,“ 218. (ZKK)
Lacquer Ground
Glaze (scratched before application of ground)
Porcelain body
Plant fibres (more than in type B) on adhesive
Type A
Lacquer
Ground
Glaze (scratched before application of ground)
Porcelain body Variant type A
Fig. 5.4. Schematic drawing on structure of substrate and layers between ground and substrate. In Type B areas of porcelain that were intended to be covered with lacquer were left unglazed, being covered with a material before firing. Either slip (a mixture of clay and water)187 or wax were applied to specific areas before glazing. In both methods the glaze would not adhere to the areas treated, and in the latter case the wax would burn away during firing188. The common salmon colour of the unglazed porcelain was suspected to have been due to remnants of the applied mass reacting with the porcelain body189 but may be simply due to oxidation of iron content in the porcelain body.190 Contours of the design may have been drawn onto these unglazed surfaces with ink.191 (App II: Fig. 68-69)
Type A but most often Type B was used for the vases from the Dresden collection, for which the porcelain surface had been prepared with an adhesive described as “dark brown, lacquer-like” made from “protein, calcium stearate and urushi” onto which “fine, plant fibres” were applied 192, in the case of type B there were more fibres than in type A193. No fibres were observed between the ground and substrate on the lacquered vases from the Rijksmuseum194 (variant type B). A third method relating to a special group of late nineteenth century Hirado vases is briefly mentioned, where linear lacquer decorations were applied to “finished blue-and-white” porcelain.195 However, details about this technique are not documented in the literature consulted.
187
Korntheuer-Wardak, "Nichtkeramische,“ 218. (ZKK) 188
Lambooy, "Lacquer on Japanese porcelain," 1076. 189
Korntheuer-Wardak, "Nichtkeramische,“ 218. (ZKK) 190 Lambooy, "Lacquer on Japanese porcelain," 1076. 191
Ströber, “Chinesische und japanische Porzellane,” 29. 192
Korntheuer-Wardak, "Nichtkeramische,“ 220. (ZKK) 193 Korntheuer-Wardak, "Nichtkeramische,“ 18. 194
Lambooy, "Japans porselein met ‘urushi’,” 43-44. 195 Lambooy, "Lacquer on Japanese porcelain," 1075.
Lacquer Ground
Material e.g. slip (applied to unglazed surface before firing, surface left salmon-coloured due to reaction with material used to cover the porcelain)
Porcelain body
Plant fibres on adhesive (less than in type A)
Type B
Wax (applied to the unglazed surface before firing has burnt away, surface left salmon-coloured due to iron in porcelain)
Lacquer
Ground
Porcelain body Variant type B
5.2.2. EUROPE
It was not known in Europe what material was used to produce lacquerware when it was first introduced in the fifteenth century, and it took until the eighteenth century until it was discovered that the sap of a tree is its source. 196 European artisans nonetheless found ways to imitate the Asian lacquer in many different ways through a practice called japanning. 197 Lacquer and Grounds
As urushi was not available outside Asia, many other materials were used as a substitute such as shellac, sandarac, gum elemi, copal resins, gum anime, amber, mastic, benzoin (gum Benjamin), dragon’s blood, gamboge, essential oils: oil of turpentine, oil of spike, camphor, and bitumen.198 Three main types of varnish were used, firstly, spirit varnishes (from the late 16th century) where the resin is dissolved in alcohol and dries by solvent evaporation (meaning the resulting lacquer is soluble in the same spirit).199 Secondly, oil or oleo-resinous varnish (from the early 18th century) which is a resin and oil drying by oxidation (meaning they are not soluble in the original solvent and overall more resistant to solvents).200 And lastly, essential oil varnishes, resin dissolved in essential oils instead of spirit or drying oil (meaning a very slow drying process).201 Grounds were usually size and whiting (animal glue and calcium carbonate) but variations existed.202
Structure of Japanned Surfaces
A typical structure for a japanned surface on wood consists of a base (or substrate), ground203 (which was not used for japanning of metal as it would only weaken the bond), varnish and decoration layers.204 Similar to the application of Japanese lacquer, polishing between application of layers are essential for getting the desired shine.205
6. PROPERTIES AND DETERIORATION
As the focus of this research is on the lacquer layer, this chapter will not go into damage issues relates to porcelain.
6.1. JAPANESE LACQUER Properties
The curing process of Japanese lacquer is undertaken in a relative humidity of at least 50% and at about 20°C degrees.206 Some sources suggest that at a relative humidity of 50% or less, it would not harden at all.207 Optimal drying conditions are sometimes described as being 70-196 Webb, Lacquer, 99. 197 Webb, Lacquer, 99. 198 Korntheuer-Wardak, "Nichtkeramische,“ 99-111. (ZKK) 199 Korntheuer-Wardak, "Nichtkeramische,“ 121. (ZKK) 200 Korntheuer-Wardak, "Nichtkeramische,“ 123. (ZKK) 201 Korntheuer-Wardak, "Nichtkeramische,“ 124-125. (ZKK) 202 Webb, Lacquer, 117.
203Victoria and Albert Museum
, “The development of English black japanning.” 204
Webb, Lacquer, 119-120. 205 Webb, Lacquer, 129-131.
80% relative humidity at 20-25°C room temperature.208 The exact curing time varies depending on the type of lacquer, the climatic conditions and the thickness of the lacquer layers. The process starts at the surface where oxygen can best reach the lacquer, the curing of the layers below is aided by humidity which helps the oxygen permeate into the lacquer. 209 To provide the humid and dust-free environment required for curing, drying cabinets are used. If the lacquer dries too fast, the top layers harden too quickly, leading to a wrinkled surface.210 This can also occur when the layers applied are too thick (App II: Fig. 70). To consider lacquer fully cured, can take nearly two months.211 A recent study that monitored thermal polymerisation of the unsaturated urushiol side chains and laccase-catalysed polymerisation, suggests the higher the temperature, the faster the hardening process.212 However, the drying process mainly depends on the oxidative polymerisation of the urushiol through the laccase enzyme (App II: Fig. 67213), which is inactive in temperatures higher than 60°C.214
Optically and chemically, newly cured urushi is very stable, being insoluble in polar solvents including water, alcohol, acids and bases.215 Once cured it is non-toxic216 and objects can be used with warm liquids217. A testimony of its great durability is the lacquerware objects that sunk in a shipwreck in the river of Nile returning to Japan from the Vienna world fair in 1873.218 The lacquerware was recovered after 18 months but has been unaffected by the prolonged submersion.219
Variations of properties between lacquers may vary depending on many factors such as the age of the tree, the harvesting time and the refinement process (elaborated in chapter 5). Moreover, if different types of lacquer have been mixed, there may be a different degree of polymerisation and therefore different flexibility and gloss.220
Surface Deterioration and Degradation due to Light and Heat
Aside from damage as a result of improper handling such as impact, abrasion and scratches, to which particularly the edges are susceptible221, lacquer is susceptible to light, heat and environmental changes as elaborated below.
Rated at blue wool standard 4222, lacquer is susceptible to photodegradation when exposed to light for prolonged periods223, leading to fragmentation of molecules and/or oxidation reactions224. Lacquer is particularly sensitive to the UV light range below 365nm, and, in a paper by Nick Umney, Kumanotani recommends no exposure below 400nm225; however, visible
208 Kumanotani, "Urushi," 168. 209 Kumanotani, "Urushi," 168. 210 Webb, Lacquer, 33.
211 McSharry, et al., "The chemistry,” 32. 212
Yang et al. "Thermal polymerization of lacquer,” 41. 213
Kumanotani, "Urushi," 164.
214 Yang et al. "Thermal polymerization of lacquer,” 41. 215
Drescher, Kintsugi Technik, 26. 216
Drescher, Kintsugi Technik, 26. 217
Drescher, Kintsugi Technik, 62. 218
Baird, "The contributions from Japan and China," 162. 219
Baird, "The contributions from Japan and China," 162. 220 Yang et al., "Thermal polymerization of lacquer,” 41. 221
Webb, Lacquer, 62-63. 222
Webb, Lacquer, 54.
223 Keneghan, "Developing a Methodology," 51. 224
McSharry, et al., "The chemistry,” 33. 225 Webb, Lacquer, 54.
