Condition Glossary

Question 1

Abrasion

Answer 1

Damage to the surface of a painting, caused by friction. Some of the surface coating, paint, or paint and ground layers are lost because of scraping or rubbing.

Other terms: rub, scrape, wear

Also: Skinning

Question 2

Accretion

Answer 2

A surface deposit of foreign material such as dried liquid residue, foodstuff, or fly specks. Accretion is an accidental addition to the painting’s surface, not foreign material intentionally included by the artist.

Other terms: surface deposit

Question 3

Auxiliary support

Answer 3

The framework over which the painting canvas is stretched. It usually refers to a stretcher or a strainer.

Other terms: secondary support

Also: Stretcher, Strainer, Support

Question 4

Bevel

Answer 4

The particular shape or cut of a stretcher or strainer bar with a top surface (adjacent to the canvas) that is planed or sanded to slope away from the back of the painting. The bevel prevents the canvas from touching the stretcher bar when ground and paint are being applied, and later prevents a stretcher mark from developing.
(Figures 1 and 2.)

Other terms: chamfer

Also: Stretcher mark

Question 5

Blanching

Answer 5

A local, opaque, whitish discoloration on the surface of a painting. Blanching occurs because of a loss of or an alteration in the binding medium in an oil film, or because of the partial dissolution of a varnish film.

Also: Bloom

Question 6

Bloom

Answer 6

Areas of white, bluish white, or yellowish cloudiness in the varnish layer that is caused by contact with moisture or certain air pollutants. Unlike blanching, bloom affects only the varnish layer

Question 7

Cleavage

Answer 7

A separation between layers of paint, between paint and ground, or between ground and support.

Also describes the delamination of layers.

Question 8

Blind cleavage

Answer 8

An invisible separation between the layers of paint, between the paint and ground, or between the ground and support. This may appear as a slight bulge in the paint surface.

Question 9

Incipient cleavage

Answer 9

Separation between layers is beginning and further separation could occur.

Also: Flaking, Lifting, Tenting

Question 10

Cockling

Answer 10

Wavy distortions or ripples in the support, usually associated with works of art on paper.

Question 11

Blister

Answer 11

A convex deformation of the ground, paint, or surface coating over an area of cleavage. Blisters are caused by excessive heating, poor adhesion between layers of a painting, moisture, or solvent action. A blister may be a form of blind cleavage.

Question 12

Crack

Answer 12

A break within one or more of the varnish, paint, or ground layers.

Question 13

Alligator cracks

Answer 13

A pattern of drying cracks that resemble alligator skin and that are associated with the different drying rates of the paint layers. The cracks have rounded edges and are often wide, exposing paint or ground layers below. Although frequently disfiguring, this paint condition is normally stable.

Other term: alligatoring

Question 14

Craquelure

Answer 14

A network of random cracks over the surface of a painting. Craquelure is caused by drying, by aging, or by changes in relative humidity.

Other term: crackle

Also: Crack

Question 15

Cupping

Answer 15

A condition where islands of paint, separated by cracks, develop concave centres with raised edges, like shallow cups.

Question 16

Cut

Answer 16

A severing of fabric or paper caused by a sharp instrument, leaving clean edges.

Also: Tear

Question 17

Draws

Answer 17

Ripples in the canvas radiating from the corners (corner draws) or edges of a painting. Draws occur during exposure to low relative humidity (e.g., during winter), and may disappear when moderate relative humidity returns.

Question 18

Delamination

Answer 18

The separation of two or more layers.

Question 19

Flaking

Answer 19

An unstable condition in which particles of paint or paint and ground become detached.

Also: Cleavage, Lifting

Question 20

Impasto

Answer 20

Pronounced brush strokes or a thick application of paint standing in relief on the surface of a painting. Impasto may be a thick or simply a slight build-up on an otherwise smooth surface.

Question 21

Lifting

Answer 21

A form of deterioration in which pieces of paint or paint and ground are partially detached and elevated above the paint surface.

Also: Cleavage, Flaking, Tenting

Question 22

Sight edge

Answer 22

he visible perimeter of a painting, not the actual edge that is hidden under the rabbet of the frame.

Question 23

Support

Answer 23

Any material, such as canvas, wood, paper, ceramic, metal, glass, ivory, or plastic, that carries the ground and paint layers.

Question 24

Surface dirt

Answer 24

A deposit of dust, dirt, grime, nicotine, soot, or other contaminant on the surface of a painting.

Also: Accretion, Grime

Question 25

Puncture

Answer 25

Hole made by impact.

Question 26

Varnish

Answer 26

Usually used as a final surface coating over a finished painting to even out the gloss, to saturate the colours, and to protect the paint.