Originally a technique for palaeobotanical work, but then refined and now used extensively in carbonate sedimentology and palaeontological work. Calcareous material is etched in a weak solution of hydrochloric acid and differences in relief are produced. After washing, the surface is flooded with acetone, and polyvinylacetate (PVA) sheeting is rolled on to the surface. The acetone softens the sheeting and moulds it to the etched rock surface. After drying the sheeting is peeled from the surface, bringing a thin layer of the surface with it. This ‘peel’ can then be examined in transmitted light. A series of peels can be taken to reveal and reconstruct buried structures and staining with various chemicals may reveal additional details.