An oil painting that has been improperly varnished or stored may develop a 'bloom' or film on the surface. This first appears as an opaque blue tinge, which turns white, yellow, and eventually black as the condition (sometimes known as a 'chill') advances
represents an approximation in dating a work of art, allowing leeway of 10 years before and after the date given.
Cleavage
"Cleavage" is sometimes used to refer to the partial separation or flaking of paint from a canvas, ground, or other layer of paint. Flaking usually reflects a breakdown in adhesion between the paint layer and the support. The problem may be inherent in an
Craquelure
graceful French term referencing cracking occurring generally in the varnish layer of a painting, but can also appear in the pigment layer.
is a conservation step taken to support a deteriorating fabric/canvas, usually employing a high quality Belgian linen that is married to the original substrate.