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Conservation & Restoration of Paintings

Before And After Of Wood Art — Scottsdale, AZ — Art Restoration By Gay Kingsley Ph.D
Paintings are usually brought to conservators or restorers only after problems in their structure or state of preservation have become obvious. Aesthetic considerations are also a common reason for consultation. Tears, water damage, heat blisters and smoke damage from a fire are clearly the result of accidents. Other damage, such as flaking, cupping, and planar distortions, may occur with time. Similarly, both varnish and pigments used for retouching, like the colors of the painting itself will discolor and change over the years. If there is a smoker in the house there can be severe discoloration! The term paintings in this context refer to works on canvas, wood panels and academy board with media including oil, acrylic, egg tempera, etc.

Tears and flaking are the two most commonly encountered problems. In both types of problems, it is advisable to call an art conservator. If flakes of paint appear loose, a painting should be removed from the wall and stored flat. It is also important that areas of flaking paint not be touched. When packed for travel to the conservatory, the painting should remain in its frame so that a rigid cover such as a piece of fome-cor or cardboard can be supported by the frame to avoid disturbing the paint.

Flaking paint may indicate one of several different conditions. On occasion, areas of flaking paint have not fully detached but have lifted away from the canvas, ground or lower paint area. This condition is referred to as cleavage. Flaking usually reflects a breakdown in adhesion between the paint layer and the support. The problem may be inherent in the artist's choice of materials or may result from the deterioration of the glue size in the ground. These conditions are aggravated by seasonal changes in temperature and humidity. The canvas or wood expands under humid conditions and contracts under dry conditions. As a paint film age, it loses its elasticity and becomes even more susceptible to flaking, cracking and cupping. In treating flaking paint, a conservator will infuse adhesive into the flaking area and apply weight during the drying period.

Tears are another major cause of the alarm. A conservator should be called immediately and the tear should be left untouched. Distortions in the canvas start to set in almost immediately and the edges become progressively more difficult to repair. Immediate treatment, even if limited is advisable. If emergency mends must be applied to the back of the painting, any pressure-sensitive tape, such as Scotch or masking must be avoided! If the painting has incurred a sizable tear a lining may be required. A lining is also required when a canvas grows too weak to support itself. If a painting has one small tear a lining should not be necessary but in an area with extreme temperature changes, a patch may start to bulge with time and a lining would be advisable.

Bulges can sometimes be eliminated by keying out the stretchers. A painting should always remain taut but it is very important that the painting not be keyed out excessively. A canvas that is too tightly stretched out on a humid day could rip apart when the humidity decreases. Old paintings on wooden frames with no keys or frames of other materials are often replaced with stretchers that can be keyed out.

Mold is usually caused by excessive moisture either in the atmosphere or from flooding. It is most commonly found on the back of the painting, where the mold or fungi feed on the binding medium in the canvas or paste in the lining. A painting with mold should be removed immediately from its damp environment. The painting should be placed in a warm, dry environment or in sunlight to prevent further growth of mold and the conservator called immediately. The painting should be placed in the sunlight, with the back towards the light, for only a short period of time and not at all in the extreme desert heat.

Beetle larvae, termites and silverfish can attack wooden panels and stretchers. I have seen them eat their way through the canvas to eat the sizing, leaving the painting in pieces. If insect damage is found, the piece must be immediately isolated an a conservator consulted about fumigating the piece. Paintings should also be protected from roaches and flies which deposit small acid specks that are nearly impossible to remove from the painted surface and can corrode both the varnish and paint.

How do I know if the artwork I buy has been restored?

When you are buying artwork, It is essential to know if the piece has been previously restored. On occasion, by simply looking at the painting, you will be able to see areas that just don t look right. If the colors in the area appear too dark compared to the surrounding area, if the texture is not the same as the rest of the painting or the painting style or strokes of paint are different in some areas this could indicate the previous restoration. If the texture of the canvas on the back of the painting is different than it appears on the face of a painting, it may mean it has been lined. Small amounts of restoration will not affect the value of the artwork but large amounts will.
You should always ask the dealer or owner and hope they are honest. They are not always honest and sometimes just don t know. In many states, a dealer does not have to disclose this information unless asked to do so. To be sure if there has been any restoration on paintings and other types of artwork you will need a UV lamp. Small portable ones are available online for as little as $19.95 which would be better than none. If you are a serious collector, you should purchase a better one with long-wave ultraviolet light in the 365-nanometer range. This range will give you the clearest visibility of surface alterations.

An ultraviolet lamp is used in a dark room where it will reveal alterations made to the artwork which are easily distinguished by the human eye. It is emitted light and not reflective light that you are seeing. Many materials absorb invisible ultraviolet energy and transform this energy into visible colored light. In some cases it is absorbed without emission, making these areas appear quite dark in contrast to the surrounding fluorescent areas. The slightest alteration to the original surface will stand out with clarity. This capability makes it an extremely useful instrument for collectors, conservators, restorers, dealers, and appraisers.

Not only are you able to see previous restoration but floating signatures, those that have been added later and are not original. You will also see areas that may have been over-cleaned during the previous restoration.

The following are various things you can look for on a painting:
  • Bluish-white spots indicate a type of lining compound coming through the canvas.
  • Chartreuse haze indicates old varnish which is very desirable.
  • Dark bluish-violet areas indicate picture repair puffy and in painting.
  • Small blue dots indicate dust.
  • Watercolor, gouache, and egg tempera may appear from pale blue to dark purple or even orange.
  • Also, be aware that the use of the new UV varnishes that protect your paintings from the UV in light also absorbs the UV frequency of a black light. It has the ability to mask the restoration. This varnish will appear to have an overall perfect coating and density of color.
  • The UV lamp can also be used with other materials such as paper art, porcelain, ceramics, textiles, stone, and ivory.

The Importance of Archival Framing of your Artwork on Paper

More than half the artwork displayed in homes today is framed or lighted in a manner that could be damaging it. If it had been framed properly, archivally, this would not be the case.

Most people purchase a frame to extend the aesthetic appeal of the artwork. As an art conservator, I take a more pragmatic approach. All artworks suffer from exposure to the environment, heat, humidity or lack of humidity. Artworks on paper pose an extra set of problems. Materials used in mounting and framing, if not archival, create an extremely hostile environment for the piece. Another term used for archival framing is conservation framing. The two terms are used interchangeably.

Conservation training aims to create a stable environment for artwork inside the frame. To accomplish this, all materials used to frame, mount and mat works of art on paper must be acid-free and should never come in contact with glass or Plexi.

There are two reasons that artwork on paper was not framed archivally.

The first reason is that if these pieces were framed in the 1950s, 1960s or earlier when archival framing did not exist. There was no acid-free mat board, no acid-free Fome Cor, and corrugated cardboard was most commonly used as backing. Many of these materials, such as corrugated cardboard contain a chemical called lignin which when touching the paper can cause discoloration, embrittlement and eventually disintegration of the paper and change of color of some pigments.

When acid-free mat board was first invented, it only came in white and cream color and people wanted color mats. There should have been a layer of acid-free or buffered paper placed between that mat and artwork but usually was not.

Another disaster was the use of dry mounting works of art on paper to acidic backings. Even as an art conservationist, I had work framed back then that I have since reframed and deacidified and bleached the artwork to remove burning caused by the acid in these materials. If a piece of artwork on paper from that time period in the original frame is purchased, it should be taken to an art conservator to be examined.

All mounting should be done with acid-free hinging or acid-free corner mounting. The best hinging is done with folded long fiber Japanese tissue and rice paste mixed with distilled water. These hinges have excellent aging properties. They are strong and flexible and allow the paper to expand and contract freely in response to changes in humidity.

Corners made from Japanese long-fibered tissue can also be used and is preferable for smaller pieces as no glue actually touches the artwork. Rice paste should still be used.

The second reason for non-archival framing is that people are not aware that it exists and don't specifically ask for it. Inexpensive chain framers very rarely mention it and still do mounting dry mounting without asking. These framers are good for framing posters, snapshots, and inexpensive artwork. They usually don't mention archival framing because of the additional cost and most people go there to get less expensive framing.

If you have a valuable or collector's piece, I advise going to a private professional framer and specifically ask for archival framing and UV glass!! The cost is more but well worth it in the long term of your investment.

UV glass or Tru Vue museum glass is very important as ultraviolet light destruction is cumulative. It is generated by natural light as well as fluorescent lights and will degrade pigment and cause fading and total loss of color over time. It will also degrade the paper even if it is archivally mounted.

Additionally, no artwork should ever touch the glazing material (glass or Plexi). That is the purpose of the mat. If you have a watercolor painting that is cockled (warped) and needs extra spacing, spacers can be used. These are narrow strips of matboard or plastic inserted around the perimeter of the frame and hidden from view by the rabbit. This technique must also be used for top-mounted, floating pieces.

Paper artwork touching the glazing in a humid environment can cause condensation and mold growth. You must have that breathing space. to accommodate the natural movement of the artwork on paper and to dissipate any trapped humidity.

I hope this will be helpful in getting you off to a good start with collecting works of art on paper.
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