Flaking. Painted artworks frequently suffer from flaking problems. Flaking is usually preceded by mechanical cracks and cupping. Cupping platelets of paint are at increased risk of coming loose from the support material (i.e., canvas, wood, etc.) and being lost, particularly if adhesion between the paint and the support is poor. Flaking paint is a very serious problem and should be addressed as soon after discovery as practicable. Conservation treatment can do a great deal to slow or eliminate flaking. The process of readhering flaking paint to the support material is called "consolidation."

About the photos. Both of the photos on the right are detail shots of paintings with flaking problems. The upper photo is of a conventional, oil-on-canvas portrait. The one on the bottom shows the reverse of a curved painting on glass from an American "banjo" clock. Paint adheres very poorly to glass, so flaking problems like this are common.

Portrait on canvas with flaking paint Painting on glass with flaking problems