While there was some controversy over whether 20th century hands should touch the master’s work, the only other choice was to allow the masterpiece to deteriorate.
The Last Supper’s restorers employed the same care that restorers ideally lavish on any artwork, great or obscure. The object is to add as little to the canvas as possible while restoring the image as close to the artist’s intention as can be determined. In recent years, advances in restoration applications include water-based conservation paints, which are fully reversible if the restorer’s “in-painting” would need to be removed. The Last Supper isn’t likely to come up at auction, but if it did, most bidders would prefer that the painting was clean and intact, allowing the artist vision to clearly shine.
Great care must be taken when restoring any work of art. It is a time and labor-intensive endeavor.
Cracked and chipped paint detracts from appreciation of the artwork as well as the asking price. The accumulation of grime that is almost inevitable, even when a painting has been well treated by owners, can also change the picture. In some cases dirt can even obscure the authorship of a work by making the painter’s signature illegible. When an artwork showing signs of deterioration comes up for auction, frequently the auction house or consignor will suggest having the painting cleaned and repaired prior to the sale. With good reason, they believe that if the work is brighter and in better shape, chances are greater that it will sell and that the winning bid will be considerably higher than if the painting was left in its dull and lackluster condition.
The mission of an art restorer is to return paintings to their original condition, enhancing both their beauty and their monetary value. All works of art can benefit from appropriate restoration; without repair an artwork will deteriorate and succumb to the environmental threats it is always exposed to.
Original works on paper as well as paint applied to canvas and various types of panels and boards respond well to professional attention. Paper restoration includes watercolor, gouache and charcoal as well as etchings such as woodcuts, steel, copper, stone and drypoint. Within these applications, it takes a skilled technician, knowledgeable of these materials and their properties, to recognize deterioration and its extent and determine what can be done to repair and preserve the condition of the piece.
Pieces kept in a hot and dry house will be affected differently from those in a cold and damp garage. Oil paintings on canvas are susceptible to the common environmental threats of humidity or alternatively, lack of moisture in the air. In areas of extreme heat, canvas can become dry and brittle and paint can reticulate or separate. Reconditioning the surface and in some cases re-lining the canvas can repair and prevent further damage. When a painting is exposed to water or extreme humidity, the canvas or board can acquire mold. A swift and comprehensive course of repair must be rendered to stop the mold migration and prevent further corruption.
One of the best preventive defenses for preserving works on canvas is the application of varnish when an oil painting is completed or cleaned. The varnish becomes a protective barrier between the paint and the environment. When a canvas becomes soiled from age or the environment, the restorer is removing the layer of varnish that has become dull and discolored from its own breakdown as well as from the absorption of dirt and pollutants in the air. The restorer is removing the varnish; the paint beneath is undisturbed by the dirt.
Works on paper are more susceptible to damage and deterioration because paper fiber is not as durable as canvas. Paper can tear from trauma, stain from acid in its immediate environment and collect mold from moisture in the air. Additionally, inks and paint as well as the paper can fade from exposure to light. All of these issues can be addressed and repaired and correct conservation methods can be applied to prevent future damage.
When cleaning an oil painting, the restorer will work with painstaking detail one inch at a time. Touching the surface with great concentration, the technician must be on constant alert against paint loss and other potential consequences due to the abrasive chemicals being used.
Restorers are frequently presented with a work of art that has been cleaned by a novice or a do-it-yourselfer. The common result of “home repair” is paint loss due to the use of an abrasive chemical that has not been neutralized after application. The chemical will slowly eat away at the paint and eventually “skin” the area. Once there is paint loss, the integrity of the artwork has been compromised and its value diminishes. Popular and incorrect chemical materials include household cleaning products (Comet, Liquid Gold) as well as food items such as bread, onions, and lemons. All of these products are harmful and destructive to artwork and should never be considered as a cleaning method.
Frame repair is also subject to common incorrect assumptions made by the nonprofessional. Decorative embellishments on many antique frames are shaped with molds made of a hardening compound called bole. The professional constructs a mold of the pattern using bole and applies it to the frame. Many a novice will rework the molds incorrectly using plaster. Embellishments made of plaster will shrink and eventually disintegrate.
In art as in life, an old adage applies: a little knowledge can be dangerous. When professional attention cannot be engaged, it’s better to leave the artwork as is. A dirty piece has more value than a damaged one.