Is It Necessary For Oil Paintings To Be Varnished?

By Author: Anthony Keith Whitehead
Total Articles: 21
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The following article discusses the reasons why oil paintings can benefit from being varnished and looks at the complications arising from differences in the drying times of different paints and treatments.

An oil painting can quite realistically be regarded as an organic object. This is because it does not stay the same over time but undergoes certain changes. Such changes may last longer than many beginners in oil painting may realise. The organic nature of oil paint derives from the nature of the materials used to produce the paint and its constituent components, such as the pigment which gives it its colour. These are themselves subject to changes over time.

Some Problems With Oil Painting
The main difficulty with an oil painting is the time it needs to dry. Watercolours or acrylics, for instance, dry very quickly, the former being dry almost immediately and the latter within a very short time. But there are also great advantages in the longer time needed for oils to dry e.g. it means that a painting, or part of it, can be reworked, changed and further developed. But an oil painting may need between ...
... six and twelve months before it is dry.

There are a number of factors that contribute towards the length of this drying period. A major factor is the thickness of paint used. Some painters like to use an impasto approach to painting and so employ relatively, and sometimes very, thick layers of oil paint and this may involve building up the image with several successive layers of thick paint.

Each layer of paint will need a greater proportion of oil to be added and, using more oil will increase the length of the drying period. Where very thick applications of paint have been repeatedly employed, an oil painting may need more than twelve months to thoroughly dry out.

In contrast to impasto is glazing, which uses only very thin layers of paint. Even if an artist is not using glazing techniques specifically, he or she may still paint relatively thinly. Hence the drying time will be comparatively short.

Significant differences in drying time will also occur between different colours and different manufacturers of oil paint. For instance, Titanium White, dries much faster than other colours. But ingredients do vary as between different producers of oil paints and this can affect drying times.

However, Winsor & Newton manufacture an alkyd range of oil paints that become touch dry very much faster, usually overnight (although atmospheric conditions can affect this somewhat. “Touch dry”, however, means no more than that; it is not an indication of complete dryness. This simply means that it can now safely have additional layers of paint applied over the earlier one(s). Remembering this, alkyd can also be used through various mediums to which it has been added so that, mixed into a particular oil paint colour, drying time can be accelerated to a similar extent.

Protecting Oil Paintings
There are all kinds of elements in the air of which we may be unaware. These include dust, grime, tobacco and other fumes and general atmospheric pollutants.
As a result, every good oil painting needs to be protected. All of these will damage the image in some way, generally making it duller and less clear, and may affect the colour itself. The longer a painting is left unvarnished, the more danger t is in from atmospheric pollutants.

An oil painting which has been varnished will still be susceptible to such atmospheric effects, but the great benefit of varnish is that it takes the force of these effects and thus protects the paint itself. As a result, a painting which has been allowed to dry properly before varnish has been applied can have the varnish removed and the painting restored to its original state. It is then possible to re-varnish it.

Another important benefit which arises from varnishing an oil painting derives from variations in the degree of gloss of different colours and manufacturing details. Thus, if you consider a completed painting these variations will, to varying extents, affect the overall appearance. Varnishing equalises these differences and gives the picture a more uniform appearance. Obviously, you can choose a varnish which gives a high gloss finish, if that is what you prefer, or a mat finish or something in-between. Some artists mix varnishes to get the result they require (although it is safer to do this using varnishes from the same manufacturer.

It is obvious that the advantages of varnishing are considerable, and should not easily be ignored. However, perhaps the main warning for many just getting started in using oils paints, is to be patient and ensure that the oil paint has been given sufficient time to dry thoroughly. That is sometimes a little inconvenient but well worth it in the long run.

AUTHOR: A K Whitehead
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This will take you to paintingsinoil.co.uk main page of original images painted by A K Whitehead.
All the paintings in oil here are by A K Whitehead, who is aself-taught artist, and are original oils and not copies. The approach is traditional, making use of various techniques, including impasto and glazing. This link will take you to the main categories of landscapes, seascapes, snowscapes, waterscapes and still life and all are provided with free frames and fastenings. Free delivery is also included within the UK.