Caring for... > Care and conservation of oil paintings

Care and conservation of oil paintings

Paintings and their frames are made of many different materials. These include: varnish, paint, glue, canvas, wood, metal, gilding and plaster. Together they form a complex structure that is easily damaged if knocked or dropped. The materials are also sensitive to, and can be damaged by, the surrounding environment, particularly extremes and changes in humidity and heat, as well as by light and dirt (note 1).

How well a painting survives over the years depends on keeping it in a good environment and on sensible handling, storage and display.

What can go wrong
Paintings can be damaged in many ways. The canvas might be torn or punctured, or may have split at the edges. The painting might have developed sagging canvas, bulges or dents. If on panel rather than canvas, you may see splits, warps and cracks in the wood; the wood will also be susceptible to insect damage (e.g. wood worm). Even if the underlying material appears sound, you may find that the image itself has areas of cracked, loose or flaking paint, lost paint, or fading. It may have yellow/brown varnish, dirt and dust, whitening, mould or mildew on the surface. Additionally the frame may be in poor condition which places the painting at risk of physical damage.

• If you think your painting has a problem or you want to find out more about its condition, contact a paintings conservator. Save any pieces that have fallen off, however small. Keep them safely in a bag or envelope as they can nearly always be put back on.

Many of the problems identified above are caused (or made worse) by poor environmental conditions. Most of the materials in a painting respond to changes in relative humidity and temperature by expanding and contracting. If the relative humidity keeps on changing then the painting will expand and contract repeatedly; the structure will become stressed and begin to fall apart. Paint layers may crack, canvas may split, wood may split and paint flake off.

In a museum the environment can be controlled with air conditioning (normally to a relative humidity of 55% (plus or minus 5%) and temperature of 20°C (plus or minus 3°C) – colder if human comfort is not an issue), but this is not usually an option in the home. In the home, a painting can suffer quite easily from high and low humidity.

Light and dirt can also cause problems. Too much light can fade certain colours and will speed up the darkening of varnish, the more light the faster this happens. Dirt looks unsightly and may be very acid. Acid will speed up the breakdown of canvas and wood making it very brittle and vulnerable to knocks and blows.

• A conservator can advise on suitable environmental conditions for your collection, and can monitor the environment and make recommendations if adjustments need to be made.

What you can do to protect your paintings
Moving and handling
Tears, holes, scratches and dents are most likely to happen when your painting is off the wall. If you plan ahead when moving paintings, these damages can usually be avoided. For example, plan a move by making sure you have somewhere to put your painting before you move it; ideally when off the wall paintings should rest face out against a clear wall on a padded surface, away from doorways, furniture and passing people. Always make sure your hands are very clean and dry before moving a painting and make sure the painting is securely fitted into the frame. When carrying your painting, have it facing towards your body and use both hands, one to hold the edge and the other to support it from beneath. Paintings with glass or ornate frames can be heavy, assess whether you need two people before embarking on the move.

Hanging your painting
Think about the positioning of your painting in relation to accidental damage from knocking.

• Avoid hanging close to shelves, furniture or where people can knock it.
• Avoid hanging behind doors, or in busy corridors where the painting can get knocked.

You should also think about the environmental conditions in which your paintings hang. During the summer in Britain, the conditions in a well ventilated room are, in general, fairly good for paintings. However, in the winter months, extremes of temperature or relative humidity can cause problems, for example, the central heating in homes really dries out the air and causes problems; whilst rooms that suffer from damp will have high humidity and dampness encourages mould or mildew.

The following points are worth considering when hanging your paintings if you want to take steps to ensure the best possible environmental conditions.

• Try to avoid hanging over direct heat or moisture sources, for example, right over fires, radiators, heaters, hot water or central heating pipes; in bathrooms, kitchens or around swimming pools.
• Avoid hanging over or next to outdoor vents, or on damp walls.
• Avoid hanging in rooms that are well heated in the winter (paintings on wood are the most vulnerable).
• Picture lights attached to or near to the top of a painting can get hot and lead to localised heating. It is best to take advice on lighting.
• Bear in mind that paintings will build up dirt more quickly in rooms with an open fire or where people smoke.

Think about the security of your painting, and take the following steps to ensure that it is hung safely.

• Hanging fitments should be fixed to the sides of the frame, not the top. Choose a thick and solid part of the frame. Make sure screws are secure but do not push them through the front.
• Use good quality picture wire or medium gauge fishing line, run it double and trim off extra lengths.
• Attach alarms to backs of frames or backboards, not the back of the canvas or panel.

• Conservators can provide advice on methods of lighting that will not cause localised heating; they may also be able to advise on security fittings.

Housekeeping
As with all objects in your home a painting will collect dust and dirt. Dust can be removed using a very soft brush with metal elements protected so that they cannot be a cause of damage. Avoid feather dusters, sheep skin dusters, however soft, as they catch. You must be careful to check that there is no paint flaking before dusting. Do not attempt any dusting if the surface appears unstable.

If your painting has glass this will need cleaning from time to time. Always spray glass cleaner onto the cloth, not the glass. Spray well away from your painting. The use of backboards is recommended as a preventive conservation measure to protect against the accumulation of dust and dirt, as well as against knocks and accidental damage. A conservator can fit backboards to your paintings for you.

Do not attempt any repair or cleaning yourself. This is a skilled process and should only be carried out by a fully qualified conservator.

Consulting a conservator
There is much that you as an owner can do in terms of preventive conservation which will slow the deterioration of your painting and protect it from accidental damage. However there are many occasions, particularly those involving interventive treatments, in which the services of a trained paintings conservator are invaluable. Paintings conservators can provide a wide range of services, for example, they can:

• Assess the condition of your painting(s) and provide recommendations for the management of a collection.
• Assess the environmental conditions in which paintings are hung.
• Provide advice on the lighting and hanging of paintings.
• Carry out condition reports in preparation for the loan or exhibition of paintings.
• Provide advice on preparing paintings for transport.
• Carry out technical analysis to inform historical research or conservation treatments.
• Carry out treatments such as cleaning and consolidation.

Most local art galleries or museums will provide information about the history of your painting. They may also have regular sessions where you talk to both curators and conservators. Should you wish to obtain a valuation of your painting, these can normally be obtained from a reputable auction house.

Note 1 This guidance note does not cover miniatures, paintings on glass, vellum, ivory, parchment, single sheet paper or silk, or those works described as works of art on paper such as watercolours, prints, drawings or photographs.

Use the Conservation Register to Find a conservator.

© Icon, the Institute of Conservation 2006.

This article offers general guidance and is not intended to be a substitute for the professional advice of an accredited conservator. The views expressed are those of the author or authors, and do not necessarily represent the views of the Institute of Conservation. The Institute of Conservation would like to acknowledge use of the MGC publication 'Ours for Keeps' in the preparation of this text. The Institute of Conservation and its partners accept no liability for any loss or damage which may arise if this guidance is followed.

The Institute of Conservation would like to acknowledge the support of The Royal Commission for the Exhibition of 1851 in the production of this guidance information. Further information on The Royal Commission for the Exhibition of 1851 and its work is available at www.royalcommission1851.org.uk.