Conservation & Restoration Treatments
The terms "conservation" and "restoration" are often used interchangeably in the field, however, they represent two distinct activities. Conservation describes the work undertaken to stabilize the physical condition of a work of art and ensure its long-term preservation. Restoration seeks to address the aesthetic appearance of a painting and, while some condition issues cannot be reversed, the objective is to return the painting as close as possible to its original appearance while taking into account the aging that has occurred. Typically, both conservation and restoration procedures are carried out during the course of a treatment.
Consolidation of Paint Layers
Paint layers can become unstable as a result of fluctuations in relative humidity and temperature or even light physical impacts. The response of the various materials in a painting to these forces can lead to lifting, flaking and loss of the ground and paint layers. Furthermore, the artist's choice of materials and techniques may further exacerbate the deterioration of a work of art.
In cases where the painted image has become unstable, consolidation is performed to secure the original paint layers. An appropriate adhesive is selected that is both effective and compatible with the artist's materials. The adhesive is locally applied to the affected area and by means of light pressure and controlled heat, the paint layers are brought back into plane and re-adhered to the underlying support layer.
Detail of active flaking and paint loss in a wood panel painting
Structural Treatment of Canvas Paintings
Paintings on canvas are susceptible to a variety of physical damages that can affect their structural integrity and appearance. These include dents, tears and planar distortions. Left untreated, these problems can lead to further weakening of the canvas and paint loss.
Structural damages can be treated using a range on methods. Dents and planar distortions are reduced and eliminated with applications of controlled moisture and weights. Tears are repaired by realigning frayed and broken canvas threads, bringing them together and bonding the threads with a suitable adhesive.
Where severe structural damage such as large tears, extensive instability of the paint layers or acute planar distortions have occurred, lining onto a new fabric support is undertaken to stabilize the entire painting.
Re-alignment of torn canvas threads in preparation for tear mending
Structural Treatment of Panel Paintings
Paintings executed on wood panels are often highly responsive to fluctuations in temperature and relative humidity. The resulting expansion and contraction of the wood can lead to warping of the panel and flaking of the paint and ground layers. Wood planks originally glued together to form the panel may come apart from mishandling or improper framing. Interventions by previous restorers such as the application of battens or cradles to reverse can restrict the natural movement and flexing of the panel resulting in splitting of the wood support along the wood grain.
Realignment and re-gluing of failed joins is undertaken to stabilize the structure of the panel. When battens or cradles on the reverse cause excessive stress, removal of those later additions is performed to relax the wood panel and prevent severe damage. Proper framing of panel paintings is critical to ensure that the wood support is maintained in a stress free state.
Rejoining of wood planks in an oil painting on oak panel
Air pollutants, dust and grime can adversely affect the appearance of works of art. The deposition of contaminants on a painting will both darken and dull the paint layers often obscuring subtle painterly effects employed by the artist.
Removal of surface grime is accomplished by a variety of means including dry and aqueous cleaning methods. Cleaning solutions are specially formulated in the studio to carry out effective surface cleaning on a variety of painted surfaces.
Detail of an oil on canvas painting during surface cleaning
Varnish Removal & Re-varnishing
Varnishes are often applied to paintings to saturate the pigments and afford the paint surface a degree of protection. Natural resin varnishes such as dammar and mastic, while initially being almost colorless, degrade over time. Typically, these varnishes will turn noticeably yellow or amber in color and may even oxidize giving them a frosted appearance. This can severely alter the appearance of a painting shifting the hues of a painting to an overall yellow-brown tone. When deemed necessary, paintings are cleaned with a range of solvents or solvent gel mixtures formulated to efficiently and safely reduce or entirely remove degraded natural resin coatings.
After cleaning, a new layer of varnish is applied, either by brushing or spraying, to re-saturate the paint layers. Synthetic resin varnishes, which are non-yellowing and can be easily removed from the paint surface with mild solvents in the future are used.
The effect of removing a yellowed and oxidized natural resin varnish from an oil painting on canvas
Filling & In-painting of Losses
Losses and abrasions that spoil the aesthetic appearance of the painting are in-painted or retouched to reunify the composition. Prior to in-painting, losses are filled with a chalk filler to the level of the original paint surface. Texturing of the fill is also undertaken to disguise the repair. In-painting is then carried out with conservation grade pigments bound in synthetic resins which are stable and non-yellowing.
Oil paints that artists might employ are not used in conservation as they will discolor and become difficult to remove from the original paint surface with aging. The retouching of losses is carried out minimally in areas of damage to ensure that as much of the artist's original paint surface remains visible.
Retouching of losses with conservation grade pigments