唐代帝陵

                                
　　Introduction
　　Christianity was officially introduced to Danish society during the l0th century AD.The first churches, of which there is only archaeological evidence today, were wooden constructions (1). During the 12th and especially the 13th centuries a greatnumber of stone churches were built. The most frequent building materials were granite boulders or ashlars, but calcareous tufa and limestone were also used,though less frequently. In the middle of the 12th century the knowledge of tile pro-
　　duction reached Denmark, and from this time bricks were the preferred building material, not only for new constructions, but also for changes and additions to ex-isting architecture. Today, the exteriors of churches show the untreated buildingmaterial or are limewashed (2).
　　About 1700 medieval churches are preserved in Denmark. Stylistically, they can roughly be divided into two periods: the Romanesque - from the end of 11th centu-ry to the end of the 13th century, and the Gothic period - from end of the 13th cen-tury to about 1500. Basically, the Romanesque construction consisted of a fiat -ceilinged nave and choir with small windows. Sometimes an apse was added to thechoir facing east and a tower to the nave facing west. During the Gothic period churches went through major changes. Vaults were constructed, windows enlarged and additional buildings as chapels, vestries and towers were built.All churches had probably been decorated with wall paintings (3). Today, visible paintings from the earliest period up to modern times are preserved in about 600 churches. Most of the decorations represent the Catholic period from the11th centu-ry to the mid 16th century, when Protestant Reformation was introduced in 1536.
　　In a similar way as the architecture is roughly divided into two periods, the style of wall paintings can be divided accordingly: the Romanesque from the end of the 11th century to the end often the 13th century, followed by the Gothic period, which lasted until the Reformation. As we do not have any written sources about the cre-ation of those paintings, we have to look at them in the context of European art.Accordingly, it seems that the wall paintings in Denmark, especially during the ear-ly Romanesque period, were, to a great extent, executed by painters from abroad,who were probably connected to monasteries. Byzantine influence in style and i-conography indicate this presence of international contacts, and often the quality in the execution is extremely high and in keeping with other comparable works in Eu-rope. The paintings in this period are figurative, and most frequently depict motivesfrom the New Testament - often placed in regular framed friezes and painted on coloured backgrounds.
　　During the Gothic period the motives changed and included representations from the Old Testament, as well as saints. Profane motives also became part of the world of Gothic images. During the early Gothic there seems still to be quite an internationalinfluence, but with time, the works seem gradually to become more regional and probably were painted by local painters. Visually, the paintings also undergo a change. They were painted on whitewash and the white background became an im-portant artistic effect.Painting techniques
　　While discussing the issue of painting technique of the Danishwall paintings, it is important to point out the fact that there are often quite big differences in the way painters were working, even within each century. However, a rough differentiationcan be made between the techniques of Romanesque and Gothic wall paintings,though there is a continual development of our knowledge during each of these peri-ods. Because there are no existing contemporary written sources dealing with the
　　execution of Danish wall paintings, the knowledge gathered in this field is based on visual observations combined with scientific analysis.
　　Romanesque paintings
　　The preparation prior to the painting process consisted of measuring out the propor-tions and the placement of the particular elements of the composition. This process was followed by the sketching of the composition by means of incisions or outlinespainted with a brush in red or yellow colour (4). Characteristic for the Romanesque wall paintings the filling of the entire surface with colour. The basic eolours wereapplied on a fresh plaster, which was specially prepared as a ground for the paint-ings. Sometimes a thin limewash was applied on the fresh plaster before the colours were applied. In that way, a fresco effect was obtained, which presumably was theintention of the painter. However, there is no evidence of works having been divid-ed into giornate. The plaster was applied in horizontal courses (pontate) depending on the placement of the scaffolding and the joints of the pontate are often passingthrough figurative motives. The final details and outlines were painted in secco,probably using lime or organic binders (5). However, not all paintings were exe-cuted on fresh plaster. We have several examples showing that the painter had usedan already existing plaster as ground for his work, and in those cases the paintings must have been executed entirely in a secco technique. The colours in use were red and yellow ochres, ultramarine, azurite, copper greens (basic copper chlorides),cinnabar, red lead and carbon black. To those a white colour similar to lime white know as San Giovanni white can be added. In addition, gilded stucco haloes or oth-er details in stucco can occasionally be seen.
　　Gothic paintings
　　The changing of technique and materials is usually a fluent process, but, as the ar-chitectural structure changed radically with the constructions of vaults, the church rooms, as a consequence, became light and had large whitewashed surfaces. Thishad a strong influence on the style of the painting, which, as radically as the archi-tecture, found new ways of expression.
　　Typical for the Gothic period was the application of a rather rough and thick layer of limewash, which formed the ground for the painting. As in the Romanesque peri-od, the technique of Gothic paintings varies in the sense that sometimes the painterworked on a fresh limewash and in other cases on a dry ground. That means that also in this period paintings are found where colours were fixed during the process ofcarbonatisation, which might have the same effect as in the fresco technique, even though it is not comparable or identical with the classic interpretation of this term.But we also presume that either organic binders or lime was added to pigments dur-ing this period.
　　The composition - both figurative and ornamental - was sketched in more or lessdetail before me basic colours were applied. In general, the preparatory phase was not as thorough as during the Romanesque period, but it was, nevertheless, neces- sary for the painter to position the figures and other elements on the vaults and walls before applying the colours. Most frequently, this was done with an outline in red ochre. Architectural decorations on fresh plaster, however, were often incised. The Gothic paintings were also completed with details and outlines (usually black) in secco. The palette of the painter differs a little from earlier periods. Ultramarine disappeared, as well as the use of cinnabar is more seldom. Azurite had probably been in use, but we only have very little evidence, as this colour has a tendency to change into a basic copper chloride, which appears green (6). A lead tin yellow ap-peared - although seldom - and mixtures of different pigments also seem to bemore frequent (7).
　　History of conservation
　　Most medieval wall paintings were covered with limewash during he 18th and 19th centuries. The white church interior was in favour - partly as a result of a pietistic movement, but probably also because of a change in taste. But, despite the factthat many of the paintings had a Catholic content, they were tolerated after the Re-formation in 1536, and were left visible for centuries to the people attending the church. The religious change did not lead to the systematic iconoclasm which hap-pened in other parts of Europe. This is an important reason why there are about 600 churches with visible wall paintings today, and many more where the paintings are preserved behind layers of limewash.The 19th century's growing national revival also included an interest in medieval wall paintings, and a great number of uncoverings took place from the middle of the cen-tury and onwards. The very first uncovering took place in 1826 in The Holy ThreeKings ' Chapel in Roskilde Cathedral (the Royal burial - place), but the actual restoration of the 15th century wall paintings did not take place until 1855- 58.
　　The incitement behind the uncovering of the mediaeval wall paintings in the 19th century was, first of all, interest in the iconographic content of the paintings, but the artistic quality also played a role in decisions whether to preserve a painting ornot. Due to the fact that the iconographic and aesthetic factors were of such impor-tance, restoration was often limited to repainting, and, if necessary, reconstruction - not only in cases when smaller parts were missing, but also when motives weretotally lost. This often led to misintei-pretations. As the number of uncoverings in-creased, the reconstructions often were inspired by already known paintings from
　　the period under consideration. It is therefore often difficult or simply impossible to estimate the date of such paintings. The painting technique had little interest to early restorers, and hardly any effort was made to try to copy or imitate materials or methods. Lime was indeed often used as a binding medium, but animal glue and ca-sein were also frequent.
　　Visual harmony was not necessarily obtained by a completiy opaque overpaint. Also in this early period we find examples of restorations where there was a serious at-tempt to respect the state of preservation of the newly uncovered painting. Onemethod was to impregnate the painted surface with water glass in order to make the painting appear more bright, and afterwards apply a glaze, which did not intend to return the painting to its original colour power.During the first half of the 20th century attitudes to conservation gradually changed. The restoration of wall paintings became a profession, and it was recognised that this field demanded professional expertise. The augmentation became more scientif-ic and restorations were often based on preliminary investigations. Still, repainting and reconstruction did take place, but the conservator did not take the liberty of do-ing it to such a wide extent as before. Much more attention was paid to the uncov-ering process, which earlier was often done by local people, who did not cared too much about the results. Now, an important aspect was the preservation of whatwas handed down, and not the restoration of the object to its original form. For the first time one might say that preservation had priority over restoration. Documenta-tion developed, and photographs were taken before and after restoration, although this was not a regular practice. The amount of written reports also increased, and even though the main issue dealt with was the iconography of the paintings, more and more information concerning the state of preservation was included. A detailed description of methods of conservation was still not part of the tradition of report-ing, but such information occurred sporadically. At the second half of 20th century the profession rapidly moved to a more academic approach. This, first of all, wasdue to the establishment of the School of Conservation at the Royal Academy of
　　Fine Arts in Copenhagen, in 1973 (8). Here, the education of wall paintings con-servators is still based on the fundamental approach of our predecessors in the pro-fession, that lime is the basic material in the conservation and restoration of wall paintings, and that all interventions, if possible, have to be reversible.
　　Conservation today
　　For conservators today it is important to preserve all facets of the painting, and in order to live up to that goal, some general principles are set out. The purpose is to preserve the authenticity of the painting as far as possible. However, conservators working with wall paintings in churches must submit to certain aesthetic requests by the church community, as the paintings are situated in a living environment where religious ceremonies take place, and, as such, c.an not be compared to objects ex- hibited and protected in museums. Those circumstances often bring the conservator into a dilemma which focuses on the contrast between antiquarian considerations and the expectations of the congregations. In practise, conservators today consider pre- ventive conservation as paramount, and try to keep intervention to a minimum. As deterioration of wall paintings is caused by environmental factors, an important aspect is the limitation of the influence of those circumstances on objects. One of the most serious problems today is deterioration caused by salts (9) induced and in- creased by the installation of heating systems in churches, which began at the end of 19th century. All Danish churches are heated today. Apart from salt transport, climate nfluences the degree of dirt deposits on surfaces. Conscious that the deteri-oration of wall paintings, according to our experience, is predominantly a surfacephenomenon, and that deterioration escalates the moment paintings are exposed,we do not uncover wall paintings - unless a technical argument justifies this inter-vention (10). Such a technical reason could be the fact that the covering limewashlayers physically cannot support the application of another layer, or that the paint-ings are covered with limewash to which an organic or synthetic hinders was added(11).
　　The treatment of wall paintings is broadly distinguished between re- restorations ofalready exposed paintings (12) and restoration of newly uncovered decorations. Asmentioned above, paintings restored during the 19th century and to a wide extent inthe 20th century are overpainted and reconstructed. Those paintings are consideredto be historical documents of restoration, and, most often it is chosen to preservethe situation - so to say, to restore the restoration. This isdone under the condi-tion that the earlier applied methods are not harming the paintings. Another impor-
　　tant issue is that the removal of overpaint/reconstructions in many cases also consid-erably diminished the narrative value of the paintings, leaving them as archaeologi- cal relicts - a situation which in most cases is not acceptable to the congregation.
　　During the treatment of newly found paintings little as possible is attempted to be done, in order to maintain the state of preservation. Aesthetic intervention is limit-ed to the amount necessary to "read" the damaged wall painting. Treatments arebased on traditions where the main product is lime (13). Lime is used in different compositions and with different aggregates for consolidation, impregnation and re-touching. But, of course, lime also has its limitations and other materials have beenintroduced, and new methods are developing continuously.Cleaning methods are individually chosen depending on the state of preservation ofthe paint layer and kind of dirt deposited on the surface. Dry cleaning, which is afrequent method, is carried out with Wish- ab sponges (made of synthetic rubber)or "gomma pane" (14). Wet cleaning is carried out - apart from water - withsolutions of sodium bicarbonate, or under certain circumstances and with specialcare with triammoniumcitrate. In the cleaning process, and also during other proce-dures, cyclododecane or menthol appear tobe useful as a protection of paint layers,paint ground etc. prior to treatment. Impregnation with limewater has a long tradi-tion in Denmark (15), and is still in use. Alternative methods with barium hydrox-ide have been successful, but both methods are only applied when necessary, andnot a general process in conservation.
　　Consolidation and reparation of plaster and limewash layers are executed with mate-rials based on matured slaked lime, to which aggregates of different compositionsare added. Quartz sand or powdered limestone are the most frequently used aggre-gates. If a lime material is not sufficient for fixing thin paint layers we sometimeshave to accept use of a synthetic adhesive, such as Primal AC33. Retouching materials vary, but are always used in a way in which the retouchingcan be distinguished from original material. Dry pigments in limewater is a tradi-tional method, and also watercolours were also introduced in the second half of the20th century. In more recent years pastels have shown to be an appropriate materi-al, as they are easily removable, and as such reversible. As a principal no reintegra-tion is carried out on original ground, but if it is necessarily to improve the legibilityof the painting pastels are an appropriate choice. Plaster reparations without re-touching are often chosen as the aesthetic solution, especially for omanesque paint-ings. Variations in the tohe and hue of the plaster are obtained by mixing certainaggregates.
　　All restoration work is documented by a written rapport accompanied by pho-tographs in black and white, and colour slides. Photographic documentation beforeand after restoration is done by a professional photographer, while most pho-tographs taken during the course of treatment are done by conservators. All recordsare stored in the archives of the National Museum and publicly accessible. Comput-erised documentation has come into use, but unresolved issues pertaining to thepreservation of electronic data done not make this a reliable archival material for the future.
　　Organisation (16)
　　Danish churches are not listed (protected by law), and the responsibility of lookingafter the buildings, wall paintings and inventory is put into the hands ora local,democratically elected parish council (17). The council is required to make a surveyof the church every year, and a representative of the deanery is present every thirdyear. All defects have to be reported, and the council has to take initiative to havethem repaired. The financial foundation for these repairs is a special tax paid bymembers .of the church. Before a project is carried out it has to be presented to thelocal diocese. All changes and repairs of buildings or objects more than 100 yearshave to be approved by the diocese. The approval is only effectuated after consultingwith experts, among whom are professionals employed by the National Museum.One of the many assignments carried out by the National Museum is the workingout of proposals for restoration of wall paintings. The actual restoration projects areusually done by conservators employed by the Conservation Department at the Na-tional Museum (18).
　　Conclusion
　　In spite of the fact that technology and knowledge about preservation of wall paint-ings have increased during the last half century it is also a fact that wall paintingsare more threatened than ever. Changes of climatic conditions are among the mostserious problems at the present time, and this problem will increase as the demandfor comfort in the church interior ii growing. For the moment, we do not have apractical solution to that problem, because a climate adjusted to the requirements ofthe paintings will not be acceptable to the congregation: Ah additional difficulty is
　　the growing use of the church interior for other activities, such as concerts, theatreand other cultural initiatives, and this puts additional stress on wall paintings and other objects. What has now been preserved for the past 1000 years is now in dan-ger of being lost within a generation or two. If we do not find solutions through adialog with the church authorities, our most important task as c0nservators will bethe preservation of the paintings for the future by covering them up again - as theywere for a long period before'revival in 19th century!
　　Notes and References
　　1. Fragments of decorated plaster were found during an excavation in Lisbjerg church (near Aarhus) in 1997. The piaster had been applied to reeds on the wall of a wooden church.
　　2. Most of the limewashed churches are white, but red and yellow limewashes are also used in certain regions.
　　3. 'Danske Kalkmalerier' Vol 1 -7 K? benhavn 1986 - 1992
　　4. P. Bollingtoft. 'Unders? gelser af metoder og materialer i romansk monumen-talmaleri', Unpublished examination paper (1992) School of Conservation, Copen-hagen. P. B011ingtoft. 'Untersuchungen yon Massen, Massstabsvorlagen und Konstruktionsmethoden in den Monumentalmalereien der Kirchen yon Idensen und Va', in Forschungsprojekt Wandrnalerei - Schaden. Hannover (1994) pp. 54-60.
　　5. The analysis of binding media has not been very conclusive to date. The organieproducts are deteriorated and very difficult to trace. The results are often polluted by other impurities, which can be misleading in the interpretation. In spite of thisfact, the laboratory at the National Museum has obtained resuks which indicate that organic binders were in use.
　　I. Brajer and M. C. Christensen. ' The Restoration of Medieval Wall Paintings in Denmark - Ethics and Treatment Methods Based on the Case Story from Nibe Church', Zeitschrift faúr Kunsttechnologie und Konserierung 10 (1996) pp. 29- 30.
　　6. Azurite was identified in the dress of Mary in Vindeby Church (the island of Lolland). The colour appeared green, as a major part of the pigment had turned in- to a basic copper chloride.
　　K. Trampedaeh. ' Sengotisk Kalkmaleri - analysemetoder og maleteknikker ', Unpublished examination paper (1988). School of Conservation , Copenhagen, p. 47- 49 and 160.
　　7. A lead tin yellow was identified in wall paintings from the middle of the 15th cen- tury in Kvislemark Church (Southern Zealand).
　　K. Trampedach. op. cit. p. 47-49 and 194.
　　8. The education leading to a Bachelor's Degree lasts 3 years, or 5 years to a Master's Degree.
　　9. Poul Klenz Larsen, Peder Bpllingtoft. 'Desalination of a Painted Brick Vault in Kirkerup Church' ICOM- CC Preprints (2000) pp. 473 - 477Poul Klenz Larsen. 'The Development and Testing of a Salt Extracting Mortar' International Journal for Restoration of Buildings and Monuments, Vol 7, No 1
　　(2001) pp79 - 90
　　10. 'Conservation for the future: The National Museum of Denmark's Counselling Service on wallpaintings in Denmark' in Forschungsprojekt Wandrnalerei -SchadenHannover (1994) pp 160 - 161
　　11. Organic or synthetic binders were often added to limewash during the 1960s,when it was difficult to buy a well slaked lime. Because of the poor quality of lime that was available masons or painters were tempted to add other binders. In 1976 a mason, Michael J? rgensen, took the initiative to produce pit lime, thanks towhich there is access to good materials today.
　　12. Kirsten Trampedach. 'Early Restoration of Danish Wallpaintings and their Rerestoration' Les Anciennes Restaurations en Peinture Murale. SFIIC Dijon 25-27 Mars 1993 pp 131 - 141.
　　13. 'Lime- based Materials. used in Conservation of Wallpaintings in Denmark'Studies and Conservation Escperienece. Sighisoara, Romania (1995) pp 79 - 84
　　14. "Gomma Pane" is a mixture of flour, copper sulfate, sodiumcarbonate and wa-ter, which is baked before use.
　　15. Isabelle Brajer and Nicoline Kalsbeek. 'Limewater absorption and calcite crys-tal formation on a limewater - impregnated secco wall painting', Studies of Con-servation 44 (1999) pp. 145-156.
　　16. Ulla Kjeer, Karl S0ndergaard Nielsen, Kirsten Trampedach. 'Nationalmuseet i Kirken' Nationalrnuseets Arbejdsrnark. Kobenhavn (1998) pp 167 - 183 (eng-lish summery pp 182- 83)17. Elections take place every fourth year.
　　18. The department of Conservation at the National Museum employ about 100 people. The department is subdivided into the following sections: Metal, Paper and Textiles, Paintings (on canvas, wood, polychrome sculptures and decorated interi-ors in profane buildings), Furniture, Wall Paintings, Organic Materials, Laborato-ry and Administration. The Section of Wall Paintings, which also includes stoneconservation, employs nine conservators.
　　Kirsten Trampedach
　　Wall Paintings Section Leader
　　Department of Conservation
　　National Museum of Denmark

唐墓壁画国际学术研讨会论文集/陕西历史博物馆编.--西安：三秦出版社，2006.10