Aboriginal and Torres Strait Islander Cultural Material

What are the most common types and causes of damage?

As with most heritage material which is made mainly from organic materials, Aboriginal and Torres Strait Islander heritage items are vulnerable to physical damage, and to damage caused by chemical deterioration of their components.

Physical damage includes:

• scuffing, abrasion and breaks to objects caused by poor handling and/or inadequate support during storage and display;

• creasing and tearing of works on paper and canvas caused by excessive or careless use;

• splitting and curling of bark paintings due to fluctuations in relative humidity;

• woven plant fibres drying out and becoming brittle in low relative humidity conditions;

• distortion of natural resins and waxes in high temperatures;

Paint is flaking away from this wooden object. Photograph courtesy of Karen Coote, Australian Museum

• loss of paint because of fluctuations in relative humidity. Fluctuations in relative humidity can cause the paint to flake and become powdery and fall off the surface of bark paintings and carved wooden objects;

• cracking of wooden objects in low relative humidity conditions. Cracking occurs when wood dries out too quickly. This can also lead to a loss of paint from these objects;

• flaking and powdering of paints because of inadequate binder in the paint formulation. The artists make their own paints for use on barks and wooden objects, using natural ochres and mineral pigments bound with glues. Sometimes only a little bit of glue is used, and this can cause the paint to fall off;

• insect attack—insects will attack wood, feathers, seeds, fibres, human hair string, bark, paper and canvas; and

Areas of insect damage can be seen on this object. Photograph courtesy of Karen Coote, Australian Museum

• soiling caused by deposits of dust. Dust can become permanently attached to objects if components, such as natural resins and waxes, soften due to high temperatures.

Damage due to chemical deterioration includes:

• fading and discolouration of natural pigments, watercolour pigments, felt-tip pen inks and other media caused by exposure to UV radiation and high lighting levels;

• discolouration of paper due to exposure to UV radiation and high lighting levels;

• fading of feathers, woven fibres, printed fabrics, paper and unpainted wooden carvings due to exposure to UV radiation and high lighting levels;

• damage from pollutants;

• natural aging of materials which happens more rapidly when objects are exposed to extreme temperatures and high relative humidity levels; and

• deterioration caused by mould growth. Organic materials are potential food sources for mould. Conditions are very favourable to mould growth when the relative humidity remains constantly above 65%.