As you saw above example of the before and after restoration process detail from a painting, cleaning of the surface might give you an idea of how important for paintings.
This oil painting was made on cardboard by the 1950s. It is a kind of oil paint sketch which is called as a ''Pochade''. It is a painting of the ''Ismet Inonu'' who is one of the founders of the Turkish Republic. It is also known that ''Ismet Inonu'' was a live model for this sketch.
The painting belonged to the ''Painting and Sculpture Museum of Ankara'' located in the capital of Turkey. which is also the first painting and sculpture museum of the republic.