This journal article discusses techniques and problems associated with conservation of prehistoric rock paintings (pictographs, rock art), particularly Aboriginal cave paintings of northern Australia Environment, erosion, weathering, pollution, vandalism, and abrasion by animals contribute significantly to their deterioration. Conventional treatments for European mural paintings and frescoes are not applicable. Binding mediums may be absent or their identification (analysis) problematic. Pigments are applied directly to the stone without a ground (eg. plaster). As paint and support (rock) are inseparable, in-situ treatments, often in remote and inaccessible areas, are required. Synthetic polymers (eg. Bedacryl 122x, Calaton C.A./C.B., Paraloid B72) are preferable to natural resins for use as fixatives and consolidants due to superior working and aging properties, reversibility and resistance to microbiological attack. Apply to paint only. Do not interfere with salt or moisture migration. Techniques for stain removal are discussed. Consolidate before cleaning. Treatments for bark paintings in museum collections are generally successful. Fix flaking and powdery paint using 5% Bedacryl 122X in toluene, and flatten warped bark supports with polyvinyl acetate (PVA) copolymer and polythene (polyethylene) under vacuum pressure. References date from 1956-1968.