Natural drying oils as binder for paints on art objects became known already in the medieval times. Due to the good experiences with those materials, the oils were used also for wood conservation in the 19th century; with fatal consequences to
some extend. The wood softens due to irrevasible decomposition phenomenoms of the oils. A feasable method for final restoration is to be developed. Similar decomposition phenomenoms with oils were discovered with oil coated genuine wood products, which were packed to soon and therefore showed a very unpleasant odour. The oils were permanantly damaged. Therefore a later drying process became imposible. Oxidised oil coats are very strong and are only to be removed from paintings through a special technique. Exemplarily it is possible to use laser cleaning and solvent gels. In preservation of monuments and historic buildings boiling linseed oil has shown great results in removing old paint coats, since not only an impregnation but also an undercoat of the wood has been achieved. After experimenting in the paint industry with synthetic resin systems in the past, a renaissance of natural products can be seen today. Besides the fundamental
question for renewable raw materials, a trend can be seen in good and approved product features. In the field of restoration and preservation, oil paint has the advantage of appropriate aging of the surface.