Conservation Department

Object conservation

 

Conserving Aboriginal bark paintings

 

Conservation of Australian Aboriginal bark paintings is a relatively new field in which the National Gallery of Australia Conservation Department has been actively involved since 1986.¹

During this time, we have achieved significant advances in the treatment of bark paintings. Looking after bark paintings in the collection is complicated by their particular material characteristics and their cultural significance, which is so different to that of the European tradition. The concept of material permanence was, until the mid-20th century, not relevant to Aboriginal experience. The prevailing environmental conditions and the inherent properties of the materials used for bark paintings made them transient objects in their original environment and cultural context. Although a lot of time and skill was devoted to making these objects, it was the concepts behind these images and the process of their creation (often a group project), which were more important than their material realisation. The permanence of the idea and the story, perpetuated by rituals or painting sessions, could be brought to life in other ways, such as in bark painting or body painting. It is only from the latter part of the 20th century that Aboriginal art made for the public domain has entered the art market, making its permanence and longevity an important issue.²

To understand the issues involved in the preservation of bark paintings it is essential to briefly examine the materials used and how they were made from the resources available to Aboriginal artists in their everyday environment. These materials include a sheet of bark (most commonly from stringybark Eucalyptus Tetradonta); naturally occurring, mostly mineral pigments (red, white, black, and yellow); and binders used to adhere the loose pigment particles as a paint layer. Most of these raw materials have remained unchanged for decades, as evidenced by the earliest surviving examples of bark paintings dating from the mid-19th century.The binders have changed in the last 30 years, due to the influence of European art practices. Natural binders such as orchid juice or turtle eggs have been substituted with readily available, synthetic materials such as PVA [polyvinyl acetate] most commonly available in the form of the wood-glue Aquadhere. David Malangi’s work presented in the exhibition No ordinary place: the art of David Malangi, spans many years and shows the different art materials used in his paintings. This substitution brought about an aesthetic change in the appearance of the painted surface — from a relative matte, porous paint made with natural, weak binders, to a shiny, cohesive, dense layer apparent in many later paintings included in the exhibition. This change in the art practice was brought about not only by artistic experimentation with readily available materials, but also by the interest of collectors in an increased permanence of the paintings.

Another change that is noticeable in the material used in bark paintings is the incorporation of acrylic paint as a painting medium, either as a substitute for the use of pigment or used in conjunction with pigment in certain areas of the composition. The more widespread use of acrylic paint was apparent from the early 1990s. In the early days of this trend, there were problems with the quality of the paint and the resulting fragility of the paint surface. In recent years, there has been a swing back to the use of natural pigment on barks due to the discomfort some artists experienced in handling the paint medium in conjunction with the marrwat (specialised hair brush) and, in places like Yirrkala, artists have taken a decision as an arts centre to uphold strong cultural values that includes painting on bark with traditional media.³

Preservation of bark paintings, as practiced by museum and gallery conservators, necessitates a respect for Indigenous cultural traditions and a thorough understanding of the material structure and composition of bark paintings. All conservation treatments are constrained by the professional ethic of minimising intervention, to maintain the present condition of the painting. It is accepted by conservators that the original painting should not be compromised by any cosmetic treatments (such as restoration).

Most conservation problems related to bark paintings are a result of the inherent properties of the materials and techniques of their manufacture. For example, the bowing and warping of the bark support comes from the tendency of bark — as a part of a tree trunk — to return to its natural, cylindrical shape. This has little significance for the longevity of the painting; however, it often stands in conflict with the European idea of a painting, which was traditionally a perfect, flat surface. Generally accepted European frameworks for consideration of works of art need to be discarded in relation to the distinctive qualities of bark paintings. The cracking and splitting of the bark — apparent in many paintings — is due to the bark’s natural movement in response to changes in relative humidity. Frequent and rapid fluctuations in moisture levels bring about high stresses in the wood structure which are released by cracking and splitting. There is little that can be done to rectify this problem once it occurs. Preventive steps can be taken which involve maintaining stable environmental conditions during storage and display, and minimising the risk of further damage.⁴

Another common problem visible in many paintings regardless of their age is the instability of the paint layer, which is evident in the flaking paint and the resulting losses. There are many factors, which influence the long-term stability of the paint layer: they include the inherent properties of the particular pigment used, the artist’s technique of paint preparation, the resulting paint behaviour, and environmental conditions to which the painting was subjected during its life. Each painting has its own unique characteristics and needs to be carefully examined by a skilled conservator familiar with the art practices of Aboriginal bark painters. There is no easy cure or recipe to rectify the often serious problem of paint instability. The treatment stabilising the paint involves choosing an appropriate agent, which when carefully introduced under each flake, adheres the lifting area back to the bark support. This very time consuming treatment is only carried out locally. There is no effective and ethically acceptable preventive treatment, which can be applied to a paint layer to prevent possible damages in the future. Some owners and collectors spray bark paintings with various ‘fixatives’ in an attempt to ensure the stability of the paint. Such treatments are ineffective, as there is insufficient penetration of the ‘fixative’ through the paint layer, which usually sits on the surface. The materials used for such treatment are frequently unstable and in time show signs of ageing, such as yellowing, cracking or lifting. Once applied to the paint, these ‘fixatives’ cannot ever be removed and therefore significantly contribute to the deterioration of the painting. There is a sad evidence of such treatments on some of David Malangi’s works included in the current exhibition.

The difficulties of treating an unstable paint layer are often  exacerbated by the presence of dirt and dust, which accumulates on the surface during the life of the painting. This needs to be carefully removed before any consolidation takes place, so that the dirt is not permanently fixed to the surface. Good preventive or housekeeping measures are essential in caring for bark paintings. They are best stored flat and protected from dust to prevent any loss of paint and dust accumulation on the surface. For display, paintings on bark in the collection of the National Gallery of Australia are not framed, but presented as they have been created — without any visual boundaries. They are simply rested on brackets, or shelves and secured to the wall by an unobtrusive clip. Seriously deteriorated paintings can be displayed horizontally or at an angle to minimise the risk of any further damage.

The preservation of bark paintings is a developing and interesting field. It requires finding new approaches and solutions to all aspects of their care: often stretching established museum practices in storage, conservation and presentation as objects for display. This gradual process of evolution will bring about a new level of appreciation for Aboriginal bark paintings as a distinctive art form, unlike any other in the world.

Beata Tworek-Matuszkiewicz
Senior Conservator, Objects

notes

¹ Beata Tworek-Matuszkiewicz, ‘Bark paintings: techniques and conservation’, in Wally Caruana (ed.) Windows on the dreaming: Aboriginal painting in the Australian National Gallery, Sydney: Ellsyd Press, 1989.
² Charles P Mountford, Records of the American–Australian expedition to Arnhem Land, Melbourne: Melbourne University Press, 1956–1960.
³ See ‘Yirrkala arts bark painting’ at members.iinet.net.au/~yirrkala-arts//buku/barkpainting.
⁴ G Morales-Segovia and B Tworek-Matuszkiewicz, Storage, display and packing systems for Australian Aboriginal bark paintings in the collection of the National Gallery of Australia, ICOM-CC, vol. 2, 12th Triennial Meeting, Lyon, 1999.