By Douglas Eisele
Old World Restorations, Inc.

The "safe" cleaning of a painting requires knowledge and experience that is delicate and complex. As a painting ages, the appearance of the image is altered with an accumulation of dirt and grime. The materials that were used to create the art also change over time.
Traditional picture varnish made of natural resins like dammar and mastic have a tendency to yellow and discolor with age. Discolored varnish is not necessarily harmful to the painting, but it does obscure the image.

There are many old wives' tales and home remedies that have been tried to clean paintings. Some of my favorites are "The Potato", rolled bread, household spray cleaners, dish soap, linseed oil, furniture polish, fingernail polish remover (acetone), lighter fluid and cooking oil.

Unfortunately, these materials can cause irreversible damage to the surface and structure of a painting and should not be used. Many simply coat the surface of the painting with a layer of slime that appears to temporarily wet or clear the image.

This application eventually dries, discolors and further obscures the image. Other home remedies can permanently dissolve and wipe away portions of the paint. Covering a painting with layers of linseed or cooking oil will accelerate the deterioration of the canvas support.

Cleaning and varnish removal require a thorough understanding of art, art history, chemistry and materials science. One must have an understanding of the materials included in each layer of a painting's structure and how they may be affected by the application of cleaning agents and solvents.

Damage from improper cleaning methods and materials may not be immediately apparent. For example, improper cleaning can weaken the bond between the paint, ground and support layers, resulting in paint loss over time. Excess water used in cleaning may swell and shrink the canvas fibers, causing unnecessary tension on the paint and eventual cracking and flaking.

Paintings are typically cleaned in stages. Preliminary tests can determine the effectiveness of cleaning agents and the solubility of the varnish and paint layers. Many different materials or combinations of materials may be needed to safely clean a painting. A material or solvent that is used to remove surface dirt and grime may not effectively reduce or reverse the discolored varnish.

Cleaning agents may also react to different colors and pigments used throughout the painting. Some colors and layers are far more sensitive than others. There are paintings that simply cannot be cleaned, because the image layer is so sensitive that no known cleaning agent can effectively remove the discoloration without causing extensive damage.

Douglas Eisele is president/owner of Old World Restorations, Inc. in Cincinnati, Ohio, restorers of paintings, frames, objects, sculpture, works on paper, photographs, metals and more. You may visit the web site at www.oldworldrestorations.com  or contact Doug Eisele by phone at (513) 271-5459, Ext. 102, or email deisele@oldworldrestorations.com.

Believe it or not, this is a painting of a ship on the ocean, damaged by years
of neglect.

The same painting, partially restored (on the right side).

Damaged portrait of a young boy, prior to restoration.

Same painting, fully restored.