Care and Conservation
Oil paintings can be maintained for years of use and enjoyment provided that some
basic care and attention is given to their preservation. The conservation staff
at The Henry Ford have compiled the information in this fact sheet to help individuals
care for their objects and collections. The first step in the care of collections
is to understand and minimize or eliminate conditions that can cause damage. The
second step is to follow basic guidelines for care, handling and cleaning.
CAUSES OF DAMAGE
The primary cause of damage to oil paintings is the storage or display of paintings
in inappropriate environments. This includes display or storage in areas where there
is excessive exposure to light, high and/or fluctuating temperature and humidity
levels, dirt or insects. Damage can also be caused by careless handling and the
improper cleaning of paintings.
Excessively high light levels can cause the fading and/or darkening of paintings.
Some paintings darken so severely that the painting and its details are no longer
visible. In order to avoid damage caused by light, paintings should be displayed
in dim areas where no direct sunlight is allowed to fall on them. The suggested
light level for paintings is 200 lux. Light levels can be measured using the light
meter in a 35mm camera
High light levels also can cause damage due to excessive heat build up. The use
of lights that are positioned close to the paintings such as the commercially available
lights that are mounted to the frame or directly above it should be avoided. Diffused
spotlights should be mounted at least 10 feet from the painting to avoid potentially
damaging heat buildup.
TEMPERATURE AND HUMIDITY LEVELS
Extremes and fluctuations in temperature and humidity can cause damage to paintings
due to the expansion and contraction of the wood and fabric components of the painting.
Wood and fabric absorb moisture which causes them to swell on humid days and conversely
shrink on dry days. Paint, however, is not as resilient and can crack and flake
off as a result of expansion and contraction of the underlying wood and fabric structure.
These dimensional changes can cause the canvas to become slack and sag during the
Most fabric paintings are secured to a wooden frame that is commonly referred to
as a stretcher or strainer. Stretchers are equipped with expandable corner joints
that can be adjusted to insure that the painting remains taught. The joints can
be expanded by driving small wooden wedges into the interior corners of the stretcher
at the back of the painting. This procedure is commonly referred to as "keying out"
a painting. Paintings should not be keyed out during the winter months when the
humidity is low. The increased tension caused by keying out may cause the painting
to tear as the wooden stretcher expands during the humid spring and summer months.
The proper display and storage of paintings can be achieved by monitoring the environment
in various rooms in order to identify the best area for display or storage of paintings.
Acceptable temperature and humidity levels for paintings are as follows, keeping
in mind that fluctuations should be kept to a minimum.
Temperature 65-70 degrees F
Relative Humidity 40%-45%
Temperature 70-75 degrees F
Relative Humidity 45-55%
Inexpensive temperature and humidity sensors can be purchased from conservation
suppliers. While precise control of temperature and humidity is desirable, it is
not always practical in homes. Therefore, damage should be minimized by avoiding
extremes in temperature and humidity. This can be done by insuring that paintings
are kept away from heat sources such as furnace vents, fire places, warm lights
and direct sunlight.
Excessive humidity, as can be found in most basements, should also be avoided since
it can cause mold growth that can stain the surface of the painting
Aside from the unsightly appearance of dirt on a painting, dirt also serves as a
host for mold growth and the absorption of pollutants and moisture onto the surface
of a painting. All of these can cause damage that obscures the image of the painting.
Paintings should not be displayed in smoking areas or in close proximity to candles
or fireplaces which can deposit nicotine and soot onto the surface of the painting.
In general, the cleaning of paintings should be left in the hands of a trained conservator.
However, there are some simple procedures that can be followed to increase the longevity
of a painting.
Soft brushes can be used to remove surface dirt from paintings and frames. When
dusting an oil painting care should be taken not to flex the canvas or to dislodge
paint chips by bumping the painting. Paintings that have loose flaking paint should
not be dusted as fragments of paint could be dislodged and swept away.
The back of the painting should be kept clean by brushing or vacuuming. In order
to clean the back, the painting should be removed from its picture frame and placed
face down on a clean surface. Excessive dirt should be vacuumed using a small low
suction nozzle with a brush attachment. Proper framing with a dust cover on the
back of the painting will prevent dirt from accumulating behind the painting.
Holiday decorating in a manner that will cause damage to paintings should also be
avoided. Live greens and berries can stain and damage frames and paintings. They
also introduce pests into the environment.
If surface dirt cannot be removed by dusting, cotton swabs that have been dampened
with distilled water can be lightly rolled on the surface to remove dirt. Again,
if there is flaking paint no attempt at cleaning should be made.
Insects that can cause damage to oil paintings include carpet beetles and powder
Carpet beetles generally subsist on protein-based materials that may be included
as a sizing material on canvas paintings. Insects are most often are found at the
back of the painting between the canvas and stretcher. Holes in the canvas, or the
presence of worm-like insects or furry carcasses are an indication of carpet beetle
problems. Powder post beetles characteristically bore small holes (approx. 2mm in
diameter) into wooden materials. These holes are generally the first visible evidence
of powder post beetle infestation. Frass, a substance that looks like saw dust,
is also a good indication of an active infestation. Paintings should be routinely
taken down and examined for pests. If evidence of infestation is found, the object
should be placed in a plastic bag and isolated until it can be examined by a professional
A Handbook on the Care of Paintings Caroline Keck. Watson-Guptill Publications 1965
Conservation and Restoration of Works of Art and Antiquities Volume I. Herman Kuhn.
Butterworths, London 1986
Art Objects their Care and Preservation. Freida Kay Fall. Lawrence McGilvery Co.
Dirt and Pictures Separated. United Kingdom Institute for Conservation of Historic
and Artistic Works. Papers given at the Tate Gallery. January 1990
Conservation of Paintings and Graphic Arts. International Institute for the Conservation
of Historic and Artistic Works Preprints of Lisbon Conference. 1972.
GUIDELINES FOR CARE Taking Care of Your Paintings
The greatest amount of damage to artifacts is caused by careless handling. Prior
to moving a painting, be sure to remove all jewelry, belt buckles, etc. so that
the painting is not accidentally torn or scratched while being moved. When moving
a painting, always be sure to grasp the painting from both vertical sides. Do not
hold a painting at the top of the frame or by its hanging wire. Also be careful
to insure that the picture wire does not puncture the back of the painting during
the move. It is important to avoid bumping canvas paintings as even the slightest
bump can cause future cracking of the paint surface.
Everybody knows that the Art Scene is on fire. Indian artists are getting their
share of fame and famous Indian paintings are selling for unbelievable prices. On
a less commercial note, people are increasingly looking at Art and paintings in
particular to enhance their décor or to make a statement about who they are or what
they like. Whether you buy art for love of paintings or as an investment, i.e. whether
your motivation is love or money, you need to look after these valuable pieces.
To understand how to look after a painting, you need to understand what a painting
is: a piece of the artist’s soul, an expression of an artist’s feelings, hopes and
sufferings. Yes, yes, very true, but on a more practical note, a painting is made
up of two parts: the support layer and the image layer. The support layer relates
to the canvas or paper that the painting is on plus the supporting frame or stretcher.
The image layer relates to “such stuff as dreams are made of” - the painting itself.
Artists may use primer and then the paint, which may be oil or water. Sometimes
oil paintings may be varnished to protect the painting or to saturate the colours.
The image you see when you look at a painting is an interaction of all these layers.
All the layers change and deteriorate and take on different physical characteristics
over time – varnish oxidizes with light and air, turning yellow or brown, paint
may become brittle.
The four factors that most affect the health of your painting are temperature, relative
humidity, light, i.e. visible light and ultra-violet radiation and pollution. Ideally,
paintings should be stored at a temperature between 18° to 24° C, which, of course,
would put paid to any Indian keeping any paintings for more than two generations.
But temperature is not as important as relative humidity levels. As constant air
conditioning is not feasible for most, an easier solution is to keep paintings in
internal rooms, which are less exposed to outside elements and variations in temperature.
Light is another factor that is hard to control, but UV blocking films on windows
are a practical solution and do not block natural light. Do not make the mistake
of putting traditional picture lights over your valued paintings. The heat and focused
light are very damaging to your paintings. Paintings should not be exposed to direct
sunlight. Try to use diffused lighting where you display your pieces.
Regarding dust and pollution. Dusting has to be done with extreme care and should
be avoided if there is flaking paint. According to some experts, vacuum cleaners
can be used to remove dirt from the back of dusty paintings. Another option is to
prop the painting up at a forward angle and brush it carefully, in one direction
only; using a clean, soft, dry natural hair artists’ brush, (3.5 cm. to 5 cm. tip).
You could even use a make up brush. Never use dusters or feather dusters as these
can damage the paint. More serious problems like flaking paint, torn canvas, cracks
with lifting edges, wrinkles in the canvas, mould growth, highly discoloured varnish
should be left to a professional conservator
Make sure that your paintings are hung securely. Check on hooks, nails and wires
at regular intervals. These, like everything are subject to wear and tear and a
huge falling painting can cause damage to itself as well as others. Take especial
care when you are moving paintings, two persons should always handle large paintings.
Never lift a painting from the top of the frame, hold a painting from the middle
of both sides. Handle with clean hands and remove rings, watches or anything that
can scrape the surface. Map out your route in advance and prepare the place that
you are shifting the painting to. If you have to transport the painting, pack it
securely: lay flat pieces of thermacol, cardboard, mat board or such firm material
over the front and back of your painting. Then wrap the whole in bubble wrap. Do
not keep it wrapped for too long to prevent moisture buildup, which can cause damage
to the painting.
With good artwork costing as much, or more, than fine jewellery, wise owners of
beautiful paintings should take pains to ensure that the Art they are lucky enough
to possess, will be enjoyed for generations to come.