Restoration, Conservation, Preservation
Conservation and Preservation of a Charcoal Drawing
The modern term used in the restoration of works of art is conservation. This includes all measures taken and studies made for the purpose of rehabilitating and saving damaged or deteriorated works. The art could include works made on paper or canvas, ceramics, stone/marble, metal or fiber art, and any other materials that could be involved in what is considered art. Restoration is not something you just pick up and do.
Proficiency in restoration and conservation requires a knowledge of art history as it relates to materials used in certain times, knowledge of the composition and chemistry of the materials used by the artist, and the methods of application of those materials. Then, there is understanding the final work and how it was brought together. Since there are numerous media that can be restored, each requiring unique procedures, this article will briefly deal with the work shown below; a charcoal study on paper.
This drawing was attached to a non-archival piece of wood pulp cardboard using staples and glue-backed tape. At some point, the backing and attached drawing a were placed behind a framed photograph. The drawing was made in 1941. It is not known when it became a backing for the photograph, but the best guess is early 1950's. I discovered the hidden drawing and had it conserved and preserved in 2013.
A decision to either conserve or restore the drawing needed to be made. Since restoration requires reproducing the chemistries of the original materials, a costly and more time consuming process, I opted for preservation, preventing further damage.
To start the process of conservation on this work, the inferior backing needed to be removed. This is traditionally a three step process.
1. After placing the drawing on a clean white surface, my conservator began by moistening the cardboard and removing thin layers, inch by inch, using a semi-sharp spatula, a process known as splitting.
2. The next step is called thinning, where the conservator uses a sharp scalpel to remove small pieces and reduce the backing to a thin skin.
3. The final step is the removal of residues, using moisture in the form of gel poultices or steam to soften the adhesive layer so it can be scraped away and lifted using a pick-up.
After turning the drawing over and placing it on another clean white surface, the next step is to clean the paper of contaminating particles to prevent further damage. Close contact with inferior products can cause yellow and/or brownish stains to leach into the body of the paper. All these were present in the drawing. Overexposure to ultraviolet light and age will cause paper to become brittle. If mold is present, it must be stabilized by placing the work in an environment with low relative humidity (less than 50%) for a prolonged period of time, causing it to go dormant before it can be removed using scalpel soft brush and suction. Luckily this was not an issue with the Lewis Bacharach charcoal.
Cleaning can involve immersing the piece in dilute baths of bleach and hydrochloric acid followed by the application of various solvents, depending on the nature of the stains. However, works done with dry media such as charcoal, pastel, or pencil, which are not firmly bound to the paper cannot be immersed into liquids.
Since this is a charcoal drawing, the only way to preserve it was by hand cleaning. Visible damages in this drawing included stains from tape and staples and at the top of the image where the paper broke due to brittleness. To lift the stains and residual glue left from the tape, plastic erasers, rubber cement pickups, soft brushes, and scalpels were used. This requires a light touch, and each time a contaminant is removed, the tool used must be cleaned. The conservator wears cotton gloves to avoid getting body oil on the work. While it may not be possible to totally remove a stain, eliminating the contaminants will prevent the stain from advancing and preserve the integrity of the paper and artwork.
The final step is conservation framing. To avoid repeat contamination, the drawing was archivally mounted on acid free board using neutral wheat paste glue and cotton based cloth. The piece was placed behind museum glass to block UV rays, preventing fading and keeping the paper from becoming brittle.
How do you find a reputable conservation house? One place to start is to ask if the conservator keeps a photographic record of the process. This should be done in conjunction with notes on procedures and chemistries. He or she may have worked on pieces with damages similar to yours, and will be able to give you an idea as to what can be done to restore and/or preserve your art. •