Conservation of historic and artistic works is a pursuit requiring special aptitudes, extensive training, and a high sense of moral responsibility. It places in the hands of the conservator cultural holdings of great value and historical significance. The conservator has obligations not only to the historic and artistic works with which he is entrusted, but also to the owners or custodians, his colleagues and trainees, his profession, the public and to posterity. It is our mission to collect, interpret, exhibit, and preserve the things which comprise our heritage.

What is Conservation?

The word CONSERVATION is used to describe a broad range of practices involved in the preservation of historic and artistic works as well as the day-to-day practice of conservation which has a concentrated focus. The American Institute for Conservation of Historic and Artistic Works (AIC) identifies the principles and practices that unite CONSERVATORS as a professional group whose members treat objects as diverse as oil paintings, steam engines, and wedding dresses.
Conservation encompasses actions taken toward the long-term preservation of cultural property. Unstable conditions occur in a painting such as tears, flaking paint and cracks. Conservation activities include the following explicit functions:

  • Examination is a procedure to determine the nature, method of manufacture or properties of objects, and the causes of their deterioration.
  • Documentation procedures record the condition of an object before, during, and after treatment, and outline in detail treatment methods and materials used.
  • Preventive Conservation is action taken to minimize further deterioration. This process includes the stabilization of the environment surrounding an artifact by methods which minimize the effects of agents of deterioration.
  • Treatment includes the stabilization of the condition of a work of art or artifact to retard or stop deterioration processes. Treatment may also include restoration.
  • Restoration is an attempt to bring cultural property closer to its original appearance or its appearance at a particular period in time.

AIC is the national membership organization of conservation professionals which coordinates and advances knowledge and improved methods of conservation needed to protect, preserve, and maintain the condition and integrity of cultural property which because of their history, significance, rarity, or workmanship have a commonly accepted value and importance for the public interest. The organization maintains a code of ethics and standards of practice which safeguard the preservation of the intrinsic character of the object.

Conservation vs Restoration: What’s the Difference?

Regarding fine art preservation, a Restorer is one who seeks to improve the appearance of a work of art with or without regard to its original structure, materials, or historic significance. In contrast, a Conservator has received a degree from a graduate-level program in conservation or completed a lengthy apprenticeship with experienced senior colleagues. A conservator has been trained to provide ethical treatment based on visual, historic, and scientific characteristics of each individual object.

Restoration; in general, repairing aesthetic appearance compromised by age or damage, is only one aspect of conservation treatment and typically follows thorough examination of the object, documentation (as per the strict Code of Ethics dictated by AIC[1] ), possible research or scientific analysis, and structural stabilization.

The contemporary field of art conservation embodies the characteristics of restoration with an understanding of the philosophy and intent inherent in the term preservation. Preservation implies saving and maintenance; restoration is the repair work necessary when an object is actually damaged or suffering from deterioration due to age or neglect. Art conservation, then, is a profession combining not only the craft traditions and many skills necessary for effective physical repairs but also a concern for history, aesthetics, uniqueness, and long-term preservation.

It is in this spirit that the Western Center for the Conservation of Fine Arts proudly offers its services and expertise in the conservation of paintings.

[1] AIC: The American Institute for Conservation of Historic and Artistic Works, a national organization of conservation professionals

What Can Happen to a Painting?

Paintings are fragile and changes are to be expected. Many changes do not threaten the stability of a painting and are not considered damage. Paintings generally do well in environmental conditions that are comfortable for people; the structural components of a painting can expand and contract in different ways as the surrounding temperature and humidity fluctuate.

Natural damages happen slowly over time

Buckling and draws; a disruption causing ridges or ripples in the canvas.

The physical components of an oil painting expand and contract in reaction to atmospheric conditions at different speeds and in unequal proportion, subjecting the painting to stress. Prolonged exposure to extremes of dryness, humidity, heat or cold with little air flow will make a painting susceptible to structural damage.

  • Panel paintings subjected to low or high relative humidity and temperatures could result in warping or splitting of the wood panel support. The wood is also susceptible to insect infestation.
  • Linen canvas subjected to high humidity will noticeably sag or loosen. This natural condition can cause buckling, draws, and support failure.

Stress cracks are caused by various types of pressure or impact in the ground and paint layers, eventually resulting in the cracking and flaking of the paint film.

Visible stress is a result of unfavorable environmental or mechanical conditions that have developed over an extended period of time.

  • Cracks, sometimes accompanied by cupping, flaking or losses may be caused by a too-damp or too-dry environment. The individual stress cracks or fissures can form a network of straight or barely curved lines.
  • Flexible canvas can become overly taut, while the more brittle paint film may crack, curl, or loosen from underlying layers.

A common sign of age is a darkened or yellowed surface caused by accumulated grime, nicotine, or discolored varnish.

Cupping; aged paint loosened by cracking, with edges curling to create cup-like formations.

  • Old varnish can be seen as a yellow or brown cast over the painted surface, obscuring the artist’s intended colors and the balance of light and dark.
  • Grime accumulation can appear as a dull grey or brownish haze caused by soot, nicotine, or ambient dust and accretions on the surface.
  • Superficial grime can become imbedded in the paint film. In some instances it can be difficult or impossible to remove.
  • Paintings displayed above a mantel will be exposed to soot, heat, and environmental extremes.
  • Exposure to direct sunlight or ultraviolet light will produce changes in the brilliance, hue, and balance of colors and will cause the paint to become brittle. Even the most permanent colors eventually will be affected by intense light.

Some events in a painting’s history may call for attention

Overpainting; the repainting is extended beyond boundaries defined by the damage.

Excessive or deteriorating restorations may appear as areas of a different color or texture than the surrounding paint.

  • These irregularities are caused by overzealous retouching of old damages, otherwise known as overpainting.
  • These areas can appear abraded or skinned (original paint removed by excessive cleaning), a sunken line caused by an improper repair of a tear, or a raised portion caused by a thick patch placed on the reverse of an old puncture or tear.

Physical damages can happen in a moment

Smoke damage; deposit of partially combusted material, usually accompanied by an odor.

Physical damage is the most common form of damage to an oil painting. Because the painted surface is traditionally not behind glass, the painting is very vulnerable, especially in transit or storage.

  • Abrasions and dent-like impressions are commonly caused by objects pressed into or rested against a painting’s surface.
  • Tears, holes, or punctures in a canvas support can be caused by poor storage or handling, household accidents, or natural disasters.
  • Issues ranging from soot deposits to disfigured paint can result from fire, an open source of heat, or hot lights. Scorched paint can be seen as a bubbled or blistered surface.
  • Water exposure can result in lifting, delamination and paint loss, wavy distortions in the canvas, mold growth, or tidelines. A saturated canvas could tighten like a drum upon drying, causing the paint surface to crack and flake immediately.

Blister; a disruption causing an area to protrude from the painted surface or a separation of the paint from the ground or both layers from the support.


Water exposure can cause paint to become extremely unstable, resulting in paint and ground loss.


Delamination; a separation of the ground, paint and varnish layers.

Cleaning an oil painting should be handled by a professional. If your painting should become soiled with food, smoke or other substances, do not attempt to clean it yourself. When structural damages occur to a painting such as tears, flaking paint, cracks with lifting edges, or mold, consult a conservator to decide on possible courses of treatment.

Painting Damage Glossary

A damaged or insecure work may be in the process of deterioration due to a weakening of materials, the structure or construction. When structural damages occur to a painting such as tears, flaking paint, cracks with lifting edges, or mold, consult a conservator to decide on possible courses of treatment. Special handling and immediate attention may be necessary.

Paint Layer Issues

Bleeding: One painted area spreads into an adjacent area; often caused by water or other solvents.

Blooming: An appearance of cloudy or dull spotting on a painting’s varnished surface as a result of exposure to moisture.

Discoloration: Changes of hue or value, often having uneven distribution and plainly detrimental to the prevailing tone relations.

Cleavage: Any separation or lifting of layers between the paint film and ground or between the ground and support. Active cleavage is generally associated with the cracking of paint and ground layers.

Blister: A protrusion from the painting’s surface as a raised area of paint indicating cleavage between the paint layer and the ground, or between two layers of paint.

Friable: An insufficient binding media causes the paint to become chalky and unstable.

Abrasions: Scratches, often resulting in a loss on the surface, extending to the paint and ground layers, caused by faulty cleaning, friction as well as where the frame touches the painted surface.

Crack/Fissure: Any separation in the paint layer, ground, or support perpendicular to the surface of the painting; not to be confused with cleavage.

Stress Cracks: Cracks caused by various types of pressure or impact in the ground and paint layers, eventually resulting in the cracking and flaking of paint film.

Traction Cracks: When the drying process is compromised the upper paint layer pulls away leaving bottom layer visible, giving the upper a raised appearance creating a pattern similar to alligator skin.

Mechanical Cracking /Spiral Cracking: Cracks caused by direct contact, resulting in the flaking and loss of paint.

Stretcher bar cracks: A line of cracks or crease in the ground or paint layer caused by repeated contact with the inner edges of the stretcher bar.

Crease: A line made by folding or wrinkling.

Aging cracks: Visible stress develops over time as a result of adverse environmental conditions, mechanical or other causes. The cracks are through all the layers of a painting appearing as individual fissures or a network of straight or barely curved lines, known as cracquelure.

Cracquelure: A network of cracks in a fine, overall pattern on the surface of a painting, usually a result of embrittlement of paint film due to age or by shrinking of the paint or varnish.

Crackle: A perpendicular disruption which causes a network of fine cracks in the painting’s layers.

Impact crackle: Cracks which form radiating circles are caused by impact.

Cupping: Aged paint, loosened by cracking, with edges curling to create cup-like formations.

Delamination: A separation of the layers of the ground, paint or varnish layers.

Interlayer Delamination: A separation of the paint and Varnish layers.

Tenting: The delamination of the paint or ground along cracks where the delaminated layers lift into a pattern resembling tent formations.

Flaking: Often through a combination of cleavage and extreme cracking, the paint or ground layer is dislodged from the support.

Lifting: The painting’s surface layers separate causing areas to lift.

Loose Paint: areas of the pigmented layer, which have lost adhesion, are no longer firmly fastened to the surface, but are still there.

Loss: A missing area in one or more layers of the painting; most frequently the result of flaking, abrasion, tears, etc.

Lacuna: A small cavity in the paint.

Surface and Coating Issues

Dirt/Grime: Dirt of any kind which accumulates on the painting’s surface.

Superficial Grime: An accumulation of dust, grease, smoke and particulate matter; generally accumulated through moisture or by transfer through inappropriate handling. Superficial grime can become imbedded, which can be difficult or impossible to remove.

Dust: Loose soil particles distributed on the surface of a painting.

Accretions: An accumulation of extraneous matter on the surface of a painting; altering the original design.

Spatter/Run: Dried droplets or splashes of foreign material.

Soil: A deposit of dirt or other materials upon the face of a painting; this may include fingerprints.

Stain: A soiled or discolored appearance caused by a foreign substance or uneven aging.

Smoke Damage: A deposit of partially combusted material, usually accompanied by an odor; generally resulting from an open flame or residue from a fireplace or a building fire.

Discolored Varnish: Natural or synthetic resin varnishes will become yellow (natural resin) or grayish (synthetic) as they age.

Canvas and Support Issues

Deformations: change or alteration of the overall form of a painting.

Warping: a structural distortion of the support whereby the support has become twisted, turned or bent out of shape, causing a planar distortion.

Buckling: A planar distortion caused by a canvas that has slackened on its stretcher, appearing as waves, ripples or bulges in the canvas. Draw: Wrinkles or bulges which radiate from edges and corners of a stretched canvas caused by an inadequate stretcher.

Cockling: A broad system of wrinkles or puckering formed on a painted surface.

Dent/Dimple: A slight depression in a painting’s surface caused by pressure, many times resulting in a puncture or hole.

Check/Split: A rupture or chink running along the wood grain; usually caused by stress.

Support Failure: Deteriorated canvas which no longer has enough strength to support a painting.

Embrittlement: The canvas has become perceptibly fragile to the point of snapping, crumbling or breaking.

Tear: A break in fabric or other sheet material as a result of tension.

Issues Caused by Previous Poor Restoration

Overpainting: Often a result of poor restoration, the repainting is extended beyond the boundaries defined by the damage.

Crushed Impasto: Heavy restoration can cause damage an artist’s distinct patterns and textural brushwork.

Skinned: Original paint is removed due to excessive cleaning.

Issues Caused by Outside Forces

Insect damage: Numerous species of insects feed upon materials in a painting, inflecting damage. Most damage occurs on the rear of the canvas, and in extreme cases can leave the paint layer unsupported, causing it to collapse. Signs of the working of insects include tunnels in wood or open gaps and holes in the fabric. Insect detritus: Debris and other feeding remains left by insects.

Water Damage: Lifting, delamination and loss of paint result from water saturation.

Tidelines: Staining on the front or reverse of the canvas caused by water coming into contact with the canvas and subsequently drying.

Shrinking: Once canvas becomes damp, drying causes the material to become smaller or more compacted.

Mold/mildew: Fungi caused by moisture, which produce enzymes that degrade the host material; until mature, neither may be detectable except by the characteristic musty odor.