http://www.kunsthaus.ch/en/the-collection/conservation/examples-from-the-world-of-art-conservation/max-ernst/puttying-and-retouching/puttying-and-retouching-3/?redirect_url=cfeiisqvffu

Kunsthaus Zürich

Puttying and retouching

Puttying and retouching

Damaged areas after fill-ins with chalk-based putty
Damaged areas after fill-ins with chalk-based putty