http://www.kunsthaus.ch/en/the-collection/conservation/examples-from-the-world-of-art-conservation/restoration-work-pierre-bonnard

Kunsthaus Zürich

Pierre Bonnard

Restoration work

The stabilization of the fragile paintwork which formed the main focus included many of the measures initiated in March 2014 after the painting had undergone intensive examination.
Lifting flakes of paint were consolidated under the microscope using a brush and a consolidant suited to the water-sensitive paintwork. Large-scale treatment of the powdery and granular surfaces was carried out without contact, using an ultrasonic nebulizer (see illustration).  This device, which is commonly used in paper restoration, converts the liquid consolidating agent into a very fine mist that can be applied evenly to the paintwork using a tube with a nozzle attached. Tiny droplets penetrate the paint layer and thus consolidate the minute loose particles.

Unsightly areas of paint loss were coloured to match the surrounding paintwork. In areas where the paint had been thickly applied, such as the dots of the red dress, paper inlays cut to size were first inserted into the losses to even out the difference in level with the remaining paintwork. Less deep areas on the other panels were retouched using crayons. Both the paper and the water-sensitive paint required the use of media containing the lowest possible concentration of water so as to avoid tide marks or glossiness, changes in colour or warping of the paper.

Consolidating the powdery paint layer using an ultrasonic nebulizer
Consolidating the powdery paint layer using an ultrasonic nebulizer
Area of paint loss and paper inlay, cut to size and ready for insertion
Area of paint loss and paper inlay, cut to size and ready for insertion
After gluing of the paper inlay and retouching
After gluing of the paper inlay and retouching