Conservation of an 18th century pastel portrait
Treatment of a pastel portrait disfigured by staining and cockling. The portrait was actively deteriorating by an acidic wooden board.
The pastel had been solidly adhered to an acidic wooden backing in the 20th century. The technique used to back the portrait had resulted in numerous air pockets between the portrait and the board. The acids from the wooden backing were migrating into the pastel portrait causing overall discoloration. Several types of stains were present. Some of the stains had been unsympathetically retouched. There were small tears around the edges of the oval portrait.
In order to stabilize the portrait, the wooden backing was removed. The cockling that had resulted from the air pockets were greatly reduced. Stains were removed. Repairs were made to make the work structurally sound.
Following treatment, the work was hinged to an archival microchamber board, the original glass was refitted and sealed to the frame to prevent dust and debris from entering. The mounted portrait was placed into its original frame and made ready for rehanging.