Abrasion: A partial or total paint loss caused by excess friction.

Binder: Medium, film forming ingredient used to bind the pigment particles together.

Blanching: A term applied when fast-evaporating solvents cool the film enough to cause water condensation causing a surface to become partially opaque, cloudy or transparent upon application or drying. 

Blister: Paint area that has separated from the ground or both layers from the support, creating a protuberation in the paintings surface

Bloom: A bluish fluorescent coat which forms on the surface of some films, the reason is linked to the object's materials.  One common is moisture  caught between varnish layers.

Burn: Blistering of a painting surface as a result of intense heat.

Chalking: Paint layer turned to powder and friable, mainly caused when there is inssuficiant binder media.

Cleaning: To remove superficial dirt, aged and discoloured varnish.

Cleaning test: Tests performed upon the varnish layer to determine the solvents or enzymes to remove the varnish without affecting the painting layers.

Craquelure: A pattern of cracks that develops on the surface of a painting due to changes in relative humidity, mechanical stress and aging of the paint film.

Consolidation: Procedure to re-adhere flaking or lack of binder defects of the paint.

Crazing: Microscopic fissures that distort light refraction which affects the appearance of haze.

Cross-linking: linking in which two or more adjacent molecules of a polymer join to form a bigger molecule. Cross-linking makes a polymer harder and raises its melting point.

Cupping: Aged paint with edges curling to create cup-like formations.

Delamination: separation of ground, paint and/or varnish layer(s).

Dent: a depression made by pressure.

Discoloration: Changes of the hues, often uneven to the original tones.

Embrittlement: When the support has become significantly fragile to the point of breaking.  

Emulsion: Is a mixture of two or more liquids, such as oil and water, which do not naturally mix together.

Facing: The adhesion of a protective layer to prevent loss of the paint during conservation treatment

Flaking: Dislodge paint or ground layer.

Fill: Material used to replace a missing area.

Friable: Insufficient binding media causing the paint to become chalky.

Gesso:  Lean layer of size and gypsum to form a ground on which to paint. Northern European Old Masters substitute gypsum with chalk.

Glaze:  A layer consisting of pigments and excess medium.  Used to add color to forms modeled in monochrome opaque paint.

Gloss: The luster of the surface of a coating. Depends in the ratio of reflected to incident light at specified angles of incidence. 

Ground: A layer of gesso or opaque paint applied to a support to provide a suitable color and texture on which to draw or paint.

Impact damage: Abrassions, tears, multiple losses cause from a mechanical impact. 

Impact crackle: Cracks in radiating circles

Inpainting: The conservation technique  to restore visual integrity of an artifact by compensating losses of media without compromising original intent or materials. 

Lacuna: Missing paint in an area.

Leaching: When solvents soluble compounds are extracted making the the paint film becomes more brittle.

Lifting: The rising of the painting surface

Lining: Auxilary support applied to the original support when its has no longer enough strength to carry the weight of the painting.

Patch: Fabric used to mend a hole or tear.

Plaster/Filling: Material used to replace missing areas of loss in the ground layer.

Pentimento: Pentimento is a change made by the artist during the process of painting. It can be detected using infra-red reflectograms and X-rays. 

Relative Humidity: is a measure of how much water is in the air compared with how much there would be if it were fully saturated at the same temperature. RH is shown as a percentage.

Retouching: See “Inpainting”

Sinking: The absorption of paint medium by a lean underlayer to produce a matte surface.

Split: rupture running along the grain of a piece of wood, usually caused by stress.

Strip lining: A lining confined to the outer edged of the painting when its necessary to strengthen the edges.

Support: Material providing the foundation for the artwork.

Support failure: Deteriorated canvas which no longer has enough strength to support the painting.

Tear: A break in fabric as a result of tension.

Varnish: Syntetic of natural resins applied as a surface film, it imparts an even gloss to the surface and protection for the surface of the artifact.