Contemporary Collections: Preprints from the AICCM National Conference 17th g 19th October 2007 Brisbane pp. 51-56
The bark used as the traditional form of substrate for Australian Aboriginal bark paintings sometimes shows spatial distortion in response to environmental variation. This can cause paint loss. However, there is little information on the cellular structure or moisture content of bark in the literature. This study identifies sieve tubes, fibres, axial parenchyma and ray parenchyma cells to be the main constituents of the bark of Eucalyptus tetrodonta and describes the changes that occur to these microstructures during its preparation as a substrate. It also shows that, when heated during the firing process of preparation, starch contained in the axial and ray parenchyma cells gelatinizes and forms a starch paste which acts to adhere the fibres, sieve tubes and parenchyma cells together. Equilibrium moisture content data indicates bark prepared by firing is less reactive to relative humidity changes.