Treatment of the work
Restoration of pastel art is a particular challenge, since the technique’s frailty limits treatment options. The colour layer is very unstable and is vulnerable to any direct contact, which complicates the conservation process, since all contact with the surface must be avoided.
... Click on the arrows in the image carousel below to see illustrations for the following explanations of the work's treatment.
1: The non-original paper are strips carefully cleaned from the edges.
2: After cleaning, we gently applied a series of canvas strips to the edges. The strips are glued on with sturgeon glue (adhesive made from dried bladder of a sturgeon) on the suction table with local suction and that is indispensable in the straightening process.
3: Remedies. The sturgeon glue in a water bath, brush, spatula, tweezers, mini spatula, canvas strip, napkin, cardboard with silicon surface for gluing.
4: Subsequent clamping of the painting on the working framework using fabric strips and adjustable pins.
Parchment and canvas in interaction
When parchment is moistened or kept in a climate with high humidity, it expands and becomes more flexible, while the canvas works in the opposite way and contracts under high humidity. This combination is ideal for this purpose, because the tension in the setups are not weakened as humidity rises, but remain (relatively) stable because of these conflicting properties.
During the humidification process in the climate chamber, all of the canvas strips were tightened by gently loosening the pin on the strip and fastenening it so it was stretched. This was repeated with all the strips several times during the humidification process. During the dehumidification process, the parchment was pulled again together and stabilised at last in the workshop's permanent climate, in a new smoothed shape.
5: Humidification in the homemade climate chamber where the relative humidity is controlled.
6: Monitoring of temperature and relative humidity with the help of dataloggers in the chamber.
7: Controlled dehumidification was ensured by slowly closing up the chamber, so the humidity could descrease and be stablised with the room’s climate. Too rapid a decrease in relative humidity will stress the parchment and can cause irregular drying and/or serious damages in the form of cracks and deformation.