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

Kunsthaus Zürich

Pierre Bonnard

Start of the restoration work

The state of conservation of the individual works was analysed using a stereomicroscope and mapped to reveal the extent of the damage and the work required. (see illustration right)

Consolidating the paint layer

In general, the areas requiring consolidation exhibit two distinct damage phenomena:

  1. Areas of intense colour application with protruding flakes of paint
  2. Areas that require treatment in their entirety because the surface is powdering owing to degradation of the binding agent.


Procedure

The first step was to consolidate the protruding flakes of paint.

A range of consolidating agents and mixtures was first tested. Very matte paints and those with insufficient binding agent have a tendency to darkening, glossiness or formation of tide marks on contact, which the restorers wanted to avoid.
Once found, the appropriate consolidating agent was then applied beneath the protruding flake with a pointed brush and pressed down with a silicone spatula.
These operations were carried out under a stereomicroscope.

All the loose areas of the paint layer have now been consolidated, and the next step will be to consolidate the sections where the paint is powdering.

Mapping of the state of conservation before work commenced. The black circles indicate areas of paint loss.
Mapping of the state of conservation before work commenced. The black circles indicate areas of paint loss.