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New art historical research on Kr\u00f8yer\u2019s late paintings was published in 2001 when Skagens Museum celebrated the 150th anniversary of Kr\u00f8yer\u2019s birth with an exhibition focusing on his late works. The central idea of the exhibition was to place the paintings in a broader artistic \u2013 and international \u2013 context. The display came in the wake of a general art historical and public interest in Kr\u00f8yer, which a number of publications and various forms of dissemination illustrate.Peder Severin Krøyer<\/em> by Peter Michael Hornung in 2002.\n\">1<\/a><\/sup>\u00a0The exhibition was followed by the 2011-2012 exhibition Kr\u00f8yer <\/em>\u2013 an international perspective <\/em>shown at The Hirschsprung Collection and Skagens Museum. This exhibition and an accompanying comprehensive publication presented the outcome of further art historical research into the artist and his European connections and sources of inspiration.<\/p>\n During preparation for Kr\u00f8yer \u2013 an international perspective<\/em> conservators from Kunstkonserveringen (The Art Conservation Center, known then as F\u00e6lleskonserveringen, in Aarhus) surveyed approximately 130 works by Kr\u00f8yer, and found recurring damage phenomena in several of his paintings from the 1880s and 1890s. The 1893 painting Summer Evening on Skagen\u2019s Beach<\/em> was examined by The National Museum of Denmark in collaboration with Kunstkonserveringen in 2005 to identify why the paint was adhering poorly to the ground.Analyse – maleri på lærred af P.S. Krøyer Sommeraften på Skagen Sønderstrand<\/em>, unpublished report, The Conservation Department, the National Museum of Denmark, Brede 2005.\n\">2<\/a><\/sup>\u00a0The many tiny losses observed could not be easily explained but attention was drawn to sand grains found in the paint, which were approximately the same size as the losses. The fact that the paint layer contained zinc white was not mentioned as a possible factor in the damage found. Considering the increasing focus on the possible side effects of zinc in oil paint,Journal of the American Institute for Conservation<\/em>, vol. 49, 2010, pp. 96-113; C.A. Maines, et al.: “Deterioration in Abstract Expressionist Paintings: Analysis of Zinc Oxide Paint Layers in Works from the Collection of the Hirshhorn Museum and Sculpture Garden”, MRS Fall Meeting – Symposium WW – Materials Issues in Art and Archaeology IX<\/em>, Smithsonian Institution 2010, Cambridge University Press, published 2011; G. Osmond: "Zinc white: a review of zinc oxide pigment properties and implications for stability in oil-based paintings.", AICCM Bulletin<\/em>, 33(1), 2012, pp. 20-29; E. Pratali: “Zinc oxide grounds in 19th and 20th century oil paintings and their role in picture degradation processes. Literary review, paint failure mechanisms and conditions of potential risk”, CeROArt. Conservation, exposition, Restauration d'Objets d'Art<\/em>, CeROArt asbl. 2013.\n\">3<\/a><\/sup> this study sets out \u2013\u00a0using non-invasive in situ techniques \u2013\u00a0to investigate the presence of zinc white and its possible role in the degradation of Kr\u00f8yer’s paintings. [fig.1]<\/strong><\/p>\n This article will focus on P.S. Kr\u00f8yer\u2019s paintings from the 1880s and 1890s by adding an interdisciplinary technical perspective to the art historical focus of recent years.4<\/a><\/sup>\u00a0The ambition is that of identifying and understanding the types of damage phenomena that have proved recurrent in the paintings of the period. These observations of damage and its extent will be described and compared to Kr\u00f8yer\u2019s use of pigments with a particular focus on white pigments.<\/p>\n Two types of deterioration are dominant on Kr\u00f8yer\u2019s paintings from the 1880s and 1890s; problems that are both related to delamination between the ground layer and the thin and brittle paint layers.<\/p>\n The first type of deterioration can be described by the term \u2018tenting\u2019. This phenomenon is characterized by a lifting of the paint and ground layers in the form of a triangular tent, when seen in profile, due to compression caused by dimensional changes in the underlying canvas support. [fig.2]<\/strong><\/p>\n Because of this compression, there is little or no space for the paint layer to return to its original position. It has been shown that these formations are not only the result of the propensity of the canvas to shrink, but are also related to the properties of the preparation layers, that is, the glue and ground layers applied to the canvas before design layers are added.Das 19. Jahrhundert und die Restaurierung: Beitr\u00e4ge zur Malerei, Maltechnik und Konservierung<\/em>, Callwey, Munich 1987.\n\">5<\/a><\/sup><\/p>\n The tent formations on Kr\u00f8yer\u2019s paintings are typically the same width as the threads in the canvas weave and most frequently occur parallel to one of the weave directions. Tenting can cause loss of paint, which usually follows the pattern of the canvas weave. [fig.3a and 3b]<\/strong> In some cases, the paint layer seems to be wrinkling as if it is too big for the support. Tenting as described here is seen in many colour are as, but it seems to be more frequent in light colours such as the large blue areas in the beach and fishermen motifs of the artist\u2019s paintings from the 1880s onwards.<\/p>\n <\/p>\n The second type of deterioration observed is minute, but extensive, losses in the paint layer due to poor adhesion between the paint and ground layers. [fig. 4a and\u00a04b]<\/strong> These losses, which are observed in all colours, can occur without visible crack formation or lifting of the paint layer, which are otherwise commonly connected to the occurrence of paint loss. The extent and amount of the losses varies from one painting to another. Both tenting and minute losses have been observed in a number of paintings from the Kr\u00f8yer \u2013 an international perspective<\/em> exhibition, but seem to be found less often in Kr\u00f8yer\u2019s early paintings and in his painted sketches on canvas.<\/p>\n A cosmopolitan at heart, Kr\u00f8yer kept himself apprised on international developments throughout his career. After his first journey to Berlin in 1875 he went abroad every year, with very few exceptions, with the objective of improving his painting skills.Kr\u00f8yer – an International Perspective<\/em>, The Hirschsprung Collection and Skagens Museum, 2012, pp. 328-333.\n\">6<\/a><\/sup>\u00a0He found inspiration in Old Master drawings and paintings, both in his younger years at the Academy of Art in Copenhagen and later on travels abroad.Kr\u00f8yer – an International Perspective<\/em>’ show his admiration of the old masters from the renaissance and baroque period. This is also confirmed by Jan Gorm Madsen’s contribution to the catalogue, ”Out into the world” p. 16: “Apparently Kr\u00f8yer was particularly interested in the old masters, whose names appear again and again on the pages of the travel diary.” And further: “But otherwise it was again names like Titian, Correggio, Giorgione, Ribera, Rubens, Rembrandt and Van Dyck that monopolized their attention.” (”Kr\u00f8yer har tilsyneladende v\u00e6ret mest optaget af de gamle mestre, hvis navne igen og igen dukker op i siderne i rejsedagbogen”; ”Men ellers var det atter navne som Tizian, Corregio, Giorgione, Ribera, Rubens, Rembrandt og Van Dyck, der stjal opm\u00e6rksomheden.”)\n\">7<\/a><\/sup>\u00a0In particular, he obtained skills in colour rendering and painterly techniques as a pupil at L\u00e9on Bonnat\u2019s school in Paris (from the summer and into the winter of 1877).<\/p>\n Due to the increasing industrialization of the production of painting materials in the 1700s and 1800s, direct knowledge of materials and their properties was no longer available to artists in the period in which Kr\u00f8yer and his contemporaries painted. This knowledge was no longer taught at the art academies, which meant that artists had to obtain it elsewhere.J.F. Willumsens maleteknik<\/em>, Willumsens Museum, Frederikssund 1992, p. 12.\n\">8<\/a><\/sup>\u00a0Kr\u00f8yer\u2019s many travels abroad\u00a0 may be seen in this light; this longing for inspiration was perhaps not so much a departure from existing tradition as a simple need to learn about new painting materials and how to use them.La Science de la Peinture<\/em> was written on the basis of teaching at the Ecole des Beaux Arts in Paris in the 1880s, and the British painter William Holman Hunt gave lectures on the topic in 1880 at the Royal Society of Arts in London. See T. Filtenborg: “J.F. Willumsens teknik”, in T. Filtenborg and V. Petersen 1992, p. 12.\n\">9<\/a><\/sup><\/p>\n Lead white had for centuries been the only white pigment that could be used in oil paint, but in 1780 an initial attempt was made to introduce the zinc oxide (ZnO) as a substitute for the highly toxic lead white. Due to economic reasons, however \u2013 zinc white being four times more expensive than lead white \u2013 this initial attempt was unsuccessful. There was also a difference in the properties of the two pigments in oil: zinc white had a clear white colour and better suspension properties, while lead white had better hiding power and drying attributes. After several attempts in France between 1835 and 1844, the hiding power of the zinc oxide pigment was improved and siccatives were introduced to improve the drying properties of the pigment in oil. As zinc manufacturing methods improved, the cost of zinc oxide decreased, and zinc white pigment became gradually more popular within the artist community. Even though zinc white was known since the Middle Ages, it was rarely used as a pigment before the 1830s. There are reports of the use of zinc white by several of Kr\u00f8yer\u2019s contemporaries in France, including Vincent van Gogh, Paul Cezanne,\u00a0\u00c9douard Manet and Camille Pissarro.Zinc white, in Artists’ pigments – a handbook of their history and characteristics<\/em>, R.L. Feller, ed., National Gallery of Art, Cambridge 1986; D. Bomford et al.: Art in the making: Impressionism<\/em>, National Gallery, London, Yale University Press 1990.\n\">10<\/a><\/sup><\/p>\n The pursuit of light was a recurring theme for Kr\u00f8yer and his international contemporaries. Kr\u00f8yer travelled to Skagen for the first time in 1882 and his rendering of the evocative twilight blue seems to reflect the myth of a special Skagen light. In fact, he was one of the first to mention a particular light in Skagen,Northern Light: Realism and Symbolism in Scandinavian Painting, 1880-1910<\/em>, Brooklyn Museum 1982. Varnedoe’s publication was the forerunner for later years’ presentations of ideas of an exclusive Nordic light and sensitivity and melancholia that fascinated an international audience.\n\">11<\/a><\/sup>\u00a0but the suggested theory of an exclusive meteorological phenomenon has been effectively refuted. SKM 100<\/em>, Skagens Museum Jubil\u00e6umsskrift 2007, pp. 128-141.\n\">12<\/a><\/sup><\/p>\n In 1889, the newly-wed Kr\u00f8yer and Marie (n\u00e9e Triepcke, 1867-1940) travelled from Germany to Denmark and then to Italy for their honeymoon. Prior to their return to Skagen in 1890, Kr\u00f8yer re-furbished his studio readying it for the work he had planned while abroad. In a letter, he requested that the walls of his studio be painted white as he wanted to work using \u201can entirely new method\u201d.13<\/a><\/sup>\u00a0He does not explain this new method further, but it can probably be seen as a continuation of his striving to convey a sense of brightness and sun on the canvas.14<\/a><\/sup>\u00a0Kr\u00f8yer\u2019s blue beach paintings from the 1890s mark a shift in his colour scheme. Although he had always worked with the rendering of light through the use of colours, in his later beach paintings he shows a special interest in brighter and lighter colours.Harmony in blue, P.S. Kr\u00f8yer's Poetic Paintings from the 1890s<\/em>, exhibition catalogue, Skagens Museum, Denmark 2001, p. 63. However, Kr\u00f8yer does not adapt the overall painterly brushwork towards complete disintegration of form that characterises impressionistic painting technique.\n\">15<\/a><\/sup>\u00a0The sea at Amalfi, one of the places he and Marie visited on their honeymoon, has been named as Kr\u00f8yer\u2019s first big inspiration for paintings dominated by sea.Peder Severin Kr\u00f8yer<\/em>, Forlaget Fogtdal 2002, pp. 238-239.\n\">16<\/a><\/sup><\/p>\n The archives of Kunstkonserveringen contain conservation treatment records from 1978 up to the present. According to the archival material, 74 Kr\u00f8yer paintings have been treated of which 59 have canvas supports. The paintings date from 1867 to 1909, thus spanning Kr\u00f8yer\u2019s complete oeuvre. Despite a lack of precision in the descriptions of structural damage on the canvas paintings, it is possible to draw some conclusions regarding recurring damage: there are frequent notes reporting weak adhesion between the paint and ground layers, and in addition, twelve records of the 59 state that there are many small losses either locally or all over the painted surface. The conservation records of Kunstkonserveringen and The National Gallery of Denmark\u00a0clearly show that water-based consolidants have been avoided for the structural treatment of Kr\u00f8yer paintings. Conservators are aware of the shrinkage risk associated with these paintings; an awareness that is based on both practical experience as well as knowledge of the negative effect of water treatments on canvas paintings from the 1800s in general.Incredible industry – preserving the evidence of industrial society<\/em>, NKF-DK, Copenhagen 2009, pp. 39-49.\n\">17<\/a><\/sup>\u00a0Thus, the files generally show that lining with a mixture of wax and resin was preferred for these paintings up until the 1970s when the conservation praxis changed towards consolidation with an acrylic polymer in solvent instead of lining.Meddelelser om konservering<\/em>, 2(7-8) 1976, pp. 223-235. Five of 23 lined paintings were lined with glue-paste adhesive and one of 12 total impregnations involved sturgeon glue.\n\">18<\/a><\/sup><\/p>\n Many of Kr\u00f8yer\u2019s late paintings tell us a story of repeated structural conservation treatments that appear to have had little positive effect on the stability of the paintings over the long term.Boys bathing at Skagen. Summer Evening<\/em>, 1899, The National Gallery of Denmark inv. no. KMS1658; Summer evening on Skagen’s South Beach<\/em>, 1893, Skagens Museum, inv. no. 1288; Summer evening at Skagen<\/em>, 1892, Ny Carlsberg Glyptotek, inv. no. MIN 0905, dep. at Skagens Museum, dep. no. 2; Fishermen at Skagen Beach<\/em>, 1883, The National Gallery of Denmark, inv. no. KMS1233; Summer evening on the Beach of Skagen, the painter and his wife<\/em>, 1899, The Hirschsprung Collection, inv. no. 234.\n\">19<\/a><\/sup>\u00a0The 1983 conservation report on the painting Summer evening on the beach at Skagen<\/em>, 1899, states that the paint is falling off in tiny pieces. This is particularly the case in the upper part of the painting, which is dominated by the blue sky and sea. [fig. 4a og 4b]<\/strong> This painting had to be impregnated six times with the acrylic binder Plexisol before the paint was considered reattached. [see table 1]<\/strong><\/p>\n <\/p>\n Table 1 and 2<\/strong><\/p>\n <\/p>\n Given the existence of numerous new industrially-produced painting materials in the 1800s, it is interesting to explore if Kr\u00f8yer employed these new materials and if the use of new materials had consequences for the paintings\u2019 technical conditions. Of the 130 Kr\u00f8yer paintings surveyed, eight paintings on canvas from the 1880s and 1890s were selected to be investigated further. [see table 1]<\/strong><\/p>\n The conservation histories of the eight art works are well documented. Paintings dominated by blue colours were selected in order to simplify the pigment examination, and of the eight paintings\u00a0five showed\u00a0or have in the past shown\u00a0the previously-described damage phenomena in the paint layers (nos. 2, 3, 6, 7 and 8), whereas three were in a good state of preservation (nos. 1, 4 and 5).<\/p>\n The pigments in the eight selected paintings were examined non-destructively using a handheld X-ray fluorescence (XRF) instrument.20<\/a><\/sup>\u00a0[fig. 5a og 5b]<\/strong> The results are summarized in table 2<\/strong>. Blue areas were tested on all of the paintings, and in cases where other colours were examined as well, those pigments are also listed in the table. The paintings were either in storage or removed from the wall so that the canvas could be examined. The ground layers were analyzed along the tacking margins, and it was found that Kr\u00f8yer used white primed canvases. The supports are assumed to be cut from rolls of pre-primed canvas, based on the fact that a smooth, continuous ground layer is present around the sides and the back of the stretcher, and no bare canvas is seen. This indicates that the canvases were not prepared directly on the stretchers. A strong lead signal was found in each case suggesting that lead white is a major component in the ground layer. The same type of ground was found by Mads Chr. Christensen and his colleagues in 2005.21<\/a><\/sup><\/p>\n <\/p>\n The most significant result of the XRF analysis is that sometime in the late 1880s, Kr\u00f8yer switched from lead white (2PbCO3<\/sub>.Pb(OH)2<\/sub>) to zinc white (ZnO) in his paint layers. None of the earlier paintings tested contain zinc, whereas all of the later artworks show the presence of zinc. There is no evidence of a mixture of white pigments in the paint layers. The shape of the XRF spectrum indicates that the lead signal in the later paintings comes from a layer behind the surface (i.e. the ground layer). [fig. 6a og 6b]<\/strong> \u00a0A single test was performed on a painting with a wooden support, which would not have the prepared lead white layer, and the only element detected that could be attributed to a white pigment was zinc. Christensen et al. found only zinc in the paint layers when they examined cross-sections using SEM-EDS.<\/p>\n Kr\u00f8yer used cobalt blue (CoO.Al2<\/sub>O3<\/sub>) in all of the analyzed paintings,\u00a0and iron was found in several paintings, suggesting the use of iron earth pigments.Zeitschrift f. Kunsttechnologie und Konservierung<\/em>, Jhr. 13, 1999, heft 1. French impressionists such as Manet, Monet, Renoir and Sisley also used the pigment, see Nicholas Eastaugh et al.: Pigment Compendium. A Dictionary of Historical Pigments<\/em>, Elsevier. Butterworth-Heinemann, Great Britain 2004.\n\">22<\/a><\/sup> Chromium was found in greener areas and is likely due to chrome oxide green or viridian (chrome oxide hydrate (Cr2<\/sub>O3<\/sub>.2H2<\/sub>O)). Antimony was identified in one early painting (no. 3) and cadmium in several. These two elements are used in the yellow pigments Naples yellow (Pb(SbO3<\/sub>)2<\/sub>) and cadmium yellow (CdS), respectively. Vermilion (HgS) was found in several of the early paintings, but in none of the later ones. Analyses of red and purple areas in the portrait of Marie Kr\u00f8yer (no. 5) found none of the inorganic elements usually associated with red pigments, which suggests that Kr\u00f8yer used organic reds in this painting.<\/p>\n Non-invasive in situ analysis of the eight paintings selected for this preliminary study showed that all of the ground layers contained lead, whereas zinc was present only in the paint layers of the investigated paintings made after 1889. The question remains as to when exactly Kr\u00f8yer started to use zinc white, and the answer is likely to be somewhere between 1884 and 1889. The introduction of this new pigment to Kr\u00f8yer\u2019s palette in the late 1880s could be a result of a familiarity with zinc white obtained while he was in France. He may have wished to take advantage of the properties of this white pigment, as it provides a cooler white tone and he may have wanted to use this quality to convey the light at Skagen in his paintings. Compared to the more opaque lead white, due to its translucency zinc white gives a brilliant and cool hue when mixed with other pigments. This property makes zinc white well-suited for depicting brightness when rendering colour without introducing too much \u2018whiteness\u2019 to the overall colour scheme. Visually the brightness in the colour tone of Kr\u00f8yer\u2019s late beach paintings is likely due to the use of zinc white. Kr\u00f8yer\u2019s wish to redecorate and repaint his studio white after his honeymoon and his mentioning of a new method may be directly reflected in his choice of pigments when he took up his Skagen motifs again.<\/p>\n Kr\u00f8yer\u2019s later palette could be examined further. This initial study found a change in his use of white pigments, but it has not yet been determined whether he altered his palette overnight or whether there was a gradual change between 1884 and 1889. This study also shows that he switched from older yellow and red pigments to newer ones, including organic reds.<\/p>\n Since damage was found in paintings from both before and after this change to zinc white, there is no basis to conclude that the delamination problems in Kr\u00f8yer\u2019s paintings can be explained exclusively by the use of zinc white, though it may add to an already existing problem. The painting formats may also be a matter of concern: smaller paintings seem to be less damaged, but the degree of slackness as well as the potential for shrinkage is greater when the formats are larger. Changing canvas production methods may be a possible explanation for the contractions causing tenting in the paint layers,\u00a0but as mentioned earlier it is also necessary to look towards possible degradation phenomena in the paint film itself.23<\/a><\/sup> The small losses may be caused by metal soap formation in the paint due to a chemical reaction between the zinc or lead in the pigments and free fatty acids from the degraded oil film.Binding medium, pigments and metal soaps characterised and localised in paint cross-sections,<\/em> PhD thesis, University of Amsterdam 2005.\n\">24<\/a><\/sup>\u00a0However, this still remains to be investigated.<\/p>\n In other words, further studies are needed to provide a more complete explanation for the paint layer damage seen in many of Kr\u00f8yer\u2019s late paintings \u2013\u00a0and in the paintings of his contemporaries. The detailed chemical and physical degradation processes in the paint film remain to be understood in order to provide a theoretical basis for future conservation of Kr\u00f8yer\u2019s works and for defining recommendations for the climatic conditions in which the works should be kept in the future.\u00a0\u00a0\u25a2<\/p>\n <\/p>\n <\/p>\n Acknowledgements<\/strong><\/p>\n The title of the article refers to A. Johansen and M.B. Jensen: Harmony in blue, P.S. Kr\u00f8yer’s Poetic Paintings from the 1890s<\/em>, exhibition catalogue, Skagens Museum, Denmark 2001.<\/p>\n The title illustration is a detail of P.S. Kr\u00f8yer:\u00a0Summer evening at Skagen<\/em>. 1892. Oil on canvas. 206 x 123 cm. Ny Carlsberg Glyptotek, inv. no. MIN 0905, dep. at Skagens Museum, dep. no. 2. Photo: Art Museums of Skagen.<\/p>\n The authors wish to thank Skagens\u00a0Museum, The National Gallery of Denmark, The Hirschsprung Collection and the Art Conservation Centre for kindly allowing us access to paintings and conservation records. A special thanks to Miriam Watts for art historical assistance and to Mikkel Scharff and J\u00f8rgen Wadum for help and inspiration.<\/p>\n","protected":false},"excerpt":{"rendered":" Degradation problems in Peder Severin Kr\u00f8yer’s paintings and the possible role of zinc white.<\/p>\n","protected":false},"author":1,"featured_media":3186,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4],"tags":[54,57,58,55,56,59],"class_list":["post-3335","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-articles","tag-conservation","tag-damage-phenomena","tag-p-s-kroeyer-en","tag-painting-technique","tag-pigments","tag-tenting-en"],"acf":[],"yoast_head":"\nThe preservation state of Kr\u00f8yer\u2019s paintings<\/h2>\n
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The artist\u2019s travels and the hunger for knowledge of materials<\/h2>\n
A new white<\/h2>\n
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Skagen and the light<\/h2>\n
The difficult task of preserving Kr\u00f8yer\u2019s late canvas paintings<\/h2>\n
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Kr\u00f8yer\u2019s palette<\/h2>\n
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<\/h2>\n
Conclusions and future perspectives<\/h2>\n