The main feature by restoring a painting is to give him back the correct readibility. The painting should not apprear as new as from the workshop of the artist, but the natural aging phenomena should and must be maintained. Basically the restorer, with the less intervention, has to give back the painting his integrity.
First step by restoring a picture is to consider the execution techinique and the state of conservation. After that the actual interventions begin. Usually the cleaning of the painting with solvents is the first step. As all interventions must be reversibel, this is impossible for the cleaning; what once was removed cannot be returned in original. This is precisely why the cleaning certainly is the riskiest intervent of all. Sometimes a simple varnish change can give back the painting the right readability and let it shine in new old splendour. The cleaning is followed by the cleaning of the back side of the canvas and the repair of cracks and holes; in some cases, depending on the condition of the painting, a doubling is needed. But generally we try to avoid this intervention as it leads to a reduction of the value. After the canvas was re-stretched on its frame we go on with the stucco work. The missing parts are filled with a paste composed of a binder and a filling, also a pigment can be added, so that the surface is adapted to the environmental color. As a final step, after the painting was coated with a first layer of varnish, we retouch the painting with retouching colours. This procedure pursues the objective to unite the work through reintegration of the chromatic tissue and mitigate the visual interference of the gaps. This reversible materials such as watercolor and tempera paints can also be used in different ways. It follows a last final layer of varnish which is sprayed over the whole surface of the painting.