Vapor Treatment: Giving Damaged Paintings a New Life

David Yanez, one of Lowy's painting conservators, is an expert in the difficult but highly effective procedure called Vapor Treatment. We talked with David about the techniques and benefits of this procedure:

Question: What is Vapor Treatment?
Yanez: Vapor Treatment is a procedure that uses small amounts of moisture, heat, pressure and solvents to relax surface distortions that occur on oil paintings.

Question: What types of problems can be helped?
Yanez: Most surface distortions, such as cupping (where cracked layers of paint curl up), dents, buckling and protrusions can be improved by the treatment.

Question: How does it work?
Yanez: A loosely woven, porous material is sprayed lightly with a water-based solution. It is then placed against the verso of the canvas and laid on a heat/vacuum table set to a low temperature. Next a large sheet of mylar is put over the entire canvas and sealed completely to the table. Suction cups attached to a vacuum pump are placed over tiny pinpricks made in the mylar, causing the vacuum to literally suck away the vapor that emanates from the moist material.
Because of this process, moisture is directed through the canvas, gesso and the paint layers, but no humidity remains on the surface or in the paint layer. Mild pressure created by the vacuum pump holds the various layers together so they cannot separate during the treatment.
This slowly administered minute amount of moisture, combined with gentle heat and mild pressure helps the paint relax into its original position in the least disruptive way possible. Think of it as a process that coaxes the paint back into place.

Question: Are other procedures needed?
Yanez: Generally, the next step is to consolidate or line the painting (as necessary) so the paint layer has a stable support.

Question: Why not just line the painting?
Yanez: In order to line a work with pronounced surface distortions like cupping, the painting must be put under high levels of pressure. This can further fracture the paint layer, and especially with newer paintings, flatten the impasto.
Another problem with lining damaged works without first performing a Vapor Treatment is weave interference. Some canvases have a weave that is so pronounced it literally imprints itself on the paint surface when heavy pressure is applied. Vapor Treatments make it possible to line a painting under mild pressure, eliminating this problem.

Question: Can Vapor Treatments be used as an alternative to lining?
Yanez: No, Vapor Treatments are used to relax the ground and paint layers back to their original form, not reattach them to their support. Infusions can be performed in conjunction with Vapor Treatment. While infusions do help consolidate and reattach ground and paint layers to their supports, results will not last as long in severe cases without a new lining. Cupping, tears and stretcher marks have a memory of their own and will eventually revert back if they have not been permanently stabilized.

Question: Are all paintings candidates for Vapor Treatments?
Yanez: Definitely not. Some canvases will shrink, causing even more damage to the paint layer. They may also be too sensitive to heat or solvents, even though we use the absolute minimum of each. Since this type of sensitivity can't be discerned with the naked eye, the only way to know is to test each canvas before any work is considered.
A successful Vapor Treatment means that the conservator has reversed the distortions of the paint and ground layers; this is one step in a series towards stabilizing deterioration and restoring damage to the work with the least invasive methods. At Lowy, we believe the job of the conservator is to preserve as much and add as little as possible.

Question: Why don't all conservators use Vapor Treatments?
Yanez: Simply put, many don't know how, because it takes years of training. Being able to test a canvas, knowing the appropriate solution, temperature and pressure level - if any one of these is wrong, a painting can be permanently damaged. In addition, some conservators don't like to spend the extra time needed for an another process, and still others don't have the necessary equipment. Administering a successful Vapor Treatment is both a science and an art, and like anything worth doing right, the technique takes time and patience to master.