Care and Conservation of Oil paintings

Kshetrimayum Kamaljit Singh *

RKCS Painting at Ibudhou Thangjing , Moirang, Manipur :: Pix - Recky Maibram

When we think of painting we usually think of oil painting. Oil painting is well not surprisingly a painting done with oil. Actually it uses oil to carry the colours. When we paint we use pigments to make the different colours. You need to have some sort of a liquid substance that you can use to carry the colours so that you can apply them. The two most commonly used liquids are water, from which we get water colours and oil which gives us oil painting. The advantage that oils have over water is that you can use a variety of different oils that all have different properties. This allows for more variations is colour and shades and it also allows for different textures on the surface of the painting.

Most oil painting is done on a canvas, traditionally this is made out of linen. However in recent years cotton has become widely used because it is cheaper. The canvas is usually stretched onto a wood frame before the painting starts. You can't apply oil based paints straight to the canvas since the acid in the paint will ruin the canvas. Before they start the painter will apply an animal glue to the canvas. They will then add several layers of white lead based paint as a primer. Finally they will add several layers of acrylic to the canvas. The acrylic layer needs to be sanded down before the painting can start. Once the canvas is ready for painting the normal technique is for the painter to sketch an outline before he starts to paint. Then he will normally add several layers of paint, this is a big part of what makes oil painting so distinctive.

After the painting is finished it normally needs to be left for up to a year to dry. Once this is done a layer of varnish is normally added to protect the painting. With all these materials like 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.

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.

o 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 even acidic. Acid will speed up the breakdown of canvas and wood making it very brittle and vulnerable to knocks and blows.

o 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?

o Moving and handling

One fundamental aspect of a painting's well-being is its safe handling. Proper handling is essential to its preservation and is the result of a professional attitude that promotes the safety of the artifact. 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.

Specific Handling Instructions

Painted edges, particularly in modern art, are considered to be an integral part of the work. It is thus important to avoid touching these "viewed edges" (normally the sides). Where handles or straps cannot be furnished, handle the edges that are least exposed to the viewer (normally the top and bottom).

Carry a small framed painting by grasping it firmly with one hand on each side.

If the painting is not framed and is small enough for one person to carry, hold it with the flat of your palms against its edges as though it were a panel freshly varnished on both sides.

Figure 1. Medium-sized paintings should be handled by two persons, each with one hand holding the lower edge or bottom comer and the other hand placed along one side towards the top corner to balance the weight of the painting.

Figure 2. Large or heavy paintings should be moved with the assistance of folding handles or nylon webbing straps secured to the reverse of the frame. When appropriate, use a trolley. Tall paintings will be more difficult to handle, as they tend to topple.

o Hanging your painting

Think about the positioning of your painting in relation to accidental damage from knocking.
I. Avoid hanging close to shelves, furniture or where people can knock it.
II. Avoid hanging behind doors, or in busy corridors where the painting can get knocked.

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

I. Try to avoid hanging over direct heat or moisture sources, for example, right over fires, radiators, heaters, and hot water or central heating pipes; in bathrooms, kitchens or around swimming pools.
II. Avoid hanging over or next to outdoor vents, or on damp walls.
III. Avoid hanging in rooms that are well heated in the winter (paintings on wood are the most vulnerable).
IV. Picture lights attached to or near to the top of a painting can get hot and lead to localized heating. It is best to take advice on lighting.
V. 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.
i. 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.
ii. Use good quality picture wire or medium gauge fishing line, run it double and trim off extra lengths.
iii. Attach alarms to backs of frames or backboards, not the back of the canvas or panel.
iv. Conservators can provide advice on methods of lighting that will not cause localized heating; they may also be able to advice on security fittings.

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

References: o ICON, The Institute of Conservation publication, 2006
o CCI notes, Canadian Conservation Institute
o Rhoadsclarke Fine Art Insurance- http://www.rhoadsclarke.com/oil-painting.php