Art restoration in the context of Conservation science (cultural heritage)

Overpainting is the final layers of paint, over some type of underpainting, in a system of working in layers. It can also refer to later paint added by restorers, or an artist or dealer wishing to "improve" or update an old image—a very common practice in the past. The underpainting gives a context in which the paint-strokes of the overpainting become more resonant and powerful. When properly done, overpainting does not need to completely obscure the underpainting. It is precisely the interaction of the two that gives the most interesting effects.

Overpainting was used extensively in many schools of art. Some of the most spectacular results can be seen in the work of Jan van Eyck.

Artwork may be damaged or destroyed as a result of various types of accidents. Damage accidents sometimes occur during exhibition or transportation. Attempts at restoration have also damaged artworks, either by expert restorers using techniques that are found decades later to be unsuitable or harmful, or simple botches by unskilled people.