They may have great monetary value or have sentimental value to their owners. Whatever the case, paintings are fragile creations that require special care to assure their continued preservation.
Paintings consist of various layers.
Traditional paintings are finished with a coat of varnish. Contemporary paintings, naive, or folk art may not have a ground layer or varnish coating. Paintings that do not have all of the traditional layers may be more fragile and susceptible to change or damage. The paint can be applied on a wide variety of supports. Although the most common are canvas and wood, other supports include paper, cardboard, pressed board, artist's board, copper, ivory, glass, plaster, and stone.