What is a Painting?

A traditional painting is constructed, in order from bottom to top, of the support, ground, paint, and coating.  The majority of paintings are on either fabric or a wooden panel.  Fabric supports are stretched over stretchers with keys (flat triangular wedges, traditionally wooden) in the corners to adjust the tension of the fabric and to prevent bulges and creases.  The ground provides a smooth surface for the paint and serves as a "sponge" to absorb excess binding media of the paint.   The paint on top of the ground can be a very thin single layer or multiple layers.   On top of the paint, there is generally a coating.  The coating, synthetic or natural resins, is used to provide saturation and to protect the paint underneath from dirt, abrasion and moisture.

Handling Paintings

Great care needs to be taken when handling paintings.  Only one painting should be handled at a time.  Large panels and canvases should be moved by two or more persons.   Be careful to keep dirt and finger prints from paintings, especially when dealing with exposed, unprimed canvases often seen in twentieth-century painting.  Make sure that your hands are clean.  You can minimize contact with the painting by wearing cotton gloves.  Any accessories such as watches or jewelry should be removed before handling paintings because they can snag or scratch the paint surface.  Carry the painting with two hands from the sides of the frame or stretcher.  Do not carry a painting by the top of the frame or stretcher.  Finally, only handle paintings that have an intact paint surface and a stable frame and stretcher.

Improper framing and loose keys should be corrected before handling.  Keys, small triangular wedges, traditionally wooden but also now available in plastic, fit into slots where the strips of the wooden stretcher join each other.  These keys regulate the outer dimensions of the stretcher frame.  Sometimes a painting may be missing some keys, having dropped out during the painting's lifetime.  New keys can be purchased at an art supply store and inserted into the slots prepared for them.

How to Hang Paintings

Appropriate sized, sturdy hardware should be used when hanging any painting.  Wall hooks should be driven into the wall studs for maximum stability.  Large, heavy paintings should also have the proper wall anchor.  Also consider mounting a bracket under the painting to help bear its weight.

Paintings may be suspended on a metal hook secured to the frame or from the appropriate weight painting (or picture) wire.  Painting (or picture) wire should be looped through eye screws, secured in the right and left sides of the frame, so that the painting hangs from a double strand of wire.  The end of the wire should be secured so that it does not poke into the back of the canvas or the panel.  The aging process makes the canvas fabric drier and weaker and any loose wire will push its way forward denting into the back of the canvas until eventually a bulge forms on the surface.  Very few people ever connect this with the unfortunate hanging method hidden from view.

All the mechanical items - moulding hangers, picture hooks, screw-eyes, cords and wires - all the metal and fabric devices whereby you painting is held in place, even if they are the best quality, should be periodically checked.  Hooks come out of plaster, screws come out of wood, wire wears out and cord rots.  Just because it hasn't fallen out yet, doesn't mean that your painting is perfectly safe.

What to do about Displaying Paintings

  • Things to Consider
    The common place to hang a painting is on a wall.  However, there are places on the wall which are bad for hanging paintings and ones which are better in terms of preservation.  The best place to hang a painting is on a wall which has a wall stud where you can securely anchor the wall hooks, away from any heat source, in a place of relatively stable and reasonable humidity and not in direct sunlight.
  • Dirt and Heat
    Heat dries out the material of the painting, speeding up the process of natural aging.   Also, as hot air rises it carries dirt with it.  Thus, a painting above a heat source will experience far more grime than is normal for the rest of the room.  Heat sources can also soften paint.  Dirt and debris are easily trapped in the softened paint and varnish.
    It is not advised to hang paintings over fireplaces.  In addition to the damage caused by the radiating heat, soot and smoke damage will permanently darken and alter the tone of the paintings, especially those paintings that are unprimed and unvarnished.
  • Water
    Moisture will weaken the adhesion of the paint layers and eventually cause paint loss.   The support and ground are the most sensitive components of the painting to water damage.  If damage to the support and ground are pervasive, further damage to the paint and varnish may occur.
  • Humidity
    Low or high relative humidity as well as rapid changes in relative humidity are not good for paintings.  Low relative humidity tends to minimize chemical change.   However, it also tends to make the paint brittle and prone to mechanical damage.   High relative humidity tends to minimize mechanical damage.  However, it tends to promote the growth of biological organisms.  Mold growth in the form of black spots has been seen in canvas paintings, especially acrylic paintings.
    Too much change in relative humidity is especially bad for wooden panel paintings.   In response to fluctuations of humidity and the shielding effect of the paint layer on top, the wooden panel has a tendency to slowly form a concave shape.   Historically, restorers have flattened the wood panel; however, in time, this procedure has caused the paint layer on the other side to flake off.  Conservators have since recommended that one should avoid applying excess pressure to constrain the natural tendency of wood to curve.
  • Light
    As a rule of thumb, ultraviolet light should be kept away from paintings, especially in display and storage.  Fugitive dyes and colorants used in the paints will eventually discolor under exposure to ultraviolet light.  The fading of pigments and dyes in paintings will affect the color balance of the image.  The intensity and wavelengths of light used in displaying graphic art is generally safe for paintings.


Provided that there are no signs of loose or flaking paint, a painting may be safely dusted using a clean, soft, natural-hair artists' brush (3.5cm to 5cm tip).  The painting should be positioned on a clean padded surface and held upright at a forward angle so the dust falls away from the face of the painting.  Brushing is carried out slowly and gently in one direction across or down the painting followed by a second brushing in the opposite direction.

Brushing painting having a matte surface (lean in binder or loaded with pigments) may burnish the painting and leave an undesirable glossy, permanent imprint.  In this case, brushing should be avoided.

Never use dry or moist dust cloths, stiff bristle brushes, or feather dusters to dust a painting.  Threads from dust cloths may catch on areas of raised paint, moisture may cause subsequent loss of paint, and both bristle-haired brushes and feather dusters can scratch the surface of a painting.

Professional Support

If you are ever in doubt about how to handle your painting of it you just want to know more about its care, paintings conservators are your best source of information.   Paintings conservators have years of education and experience working with all kinds of paintings in all sorts of conditions.  They will be able to guide you in the preservation and care of your painting so it will appear its best for the longest time.

Selected Bibliography

Carr, Dawson W. and Leonard, Mark, Looking at Paintings: a Guide to Technical Terms, Malibu, CA: The John Paul Getty Museum, 1992.
Gettens, Rutherford J. and Stout, George L., Paintings Materials, New York, NY: Dover Publications, 1966.
Gottsegen, Mark David, The Painter's Handbook, New York, NY: Watson-Guptill Publications, 1993.
Keck, Caroline K., A Handbook on the Care of Paintings, The American Association for State and Local History, 1965.
Keck, Caroline K., How to Take Care of Your Pictures, The Museum of Modern Art and The Brooklyn Museum, 1954.
Stout, George L., The Care of Pictures, New York, NY: Columbia University Press, 1948.
Thomson, Garry, The Museum Environment, 2nd edition, Boston, MA: Butterworths, 1986.