Paintings Change Over Time. Some inevitable results of aging can be increased transparency of oil paint, or the appearance of certain types of cracks. They do no necessarily threaten the stability of a painting and may not always be considered damage. One of the most common signs of age is a darkening or yellowed surface caused by accumulated grime or discolored varnish. When varnish becomes so discolored that it obscures the artist’s intended colors or the balance of lights and darks, it can usually be removed by a conservator. There can also be some evidence of aging, which is natural and should be accepted. However, when structural damages occur in a painting such as tears, flaking paint, cracks with lifting edges, or mold, SB Conservation can assess the damage and recommend a course of treatment for your painting.