C – Glossary Terms

COSHH – Control of Substances Hazardous to Health:

This is the protocol carried out to ensure safe working practices when using the various materials for conservation treatment and scientific research such as solvents.

CT Imaging (Computerised Tomography):

This combines a series of X-ray views taken from many different angles and computer processing to create cross-sectional images of the interior of an artefact (e.g. a mummy). In some cases, CT images can be combined to create 3-D images. CT scan images can provide much more information than X-rays.


Is a naturally occurring organic compound and forms a basic constituent of plants.


Powdering of the surface. Other word – powdering.

Chip (Stone):

Loss of a small amount of material as a result of a mechanical action (e.g. impact).

Chips (Organics/ Metals):

Marks or flaws made by breaking off or gouging out of a small piece of the object.


Small section or piece cut or broken off from hard material – implies loss of small amount of material often exposing fresher looking material underneath.


There are many different methods for cleaning heritage objects – dry cleaning / wet/ washing.
Conservators decide which method would most suite each object.

Clip (from paper conservation):

To hide excess paper or cover the edge of a sheet of paper – not to cut.

Coating (Ceramics/ Metals/ Stone):

A layer or film spread over a surface usually for protection. These maybe waxes, natural or synthetic resins.

Collections Care:

The overarching term given to professionals involved with the maintenance and care of a museum or gallery collection.

Concretion/Accretion (ceramics, glass, metals):

A hard surface deposit of a foreign material often from burial.


The profession devoted to the preservation of cultural property for the future.

Conservation treatment:

Is there visible evidence of recent conservation work, e.g. fills, support backing? Worth noting position of conservation repairs as this may indicate vulnerable or weakened area. May not be immediately obvious.


A professional who, through specialised education, knowledge, training and experience formulates and implements all the activities of conservation in accordance with an ethical code.


To make a fragile or crumbling material stronger.



Gradual deterioration of a metal due to chemical processes such as oxidation or the action of a chemical agent. Some corrosion products, like metal patinas, can be protective. Others, like rust, can be harmful.

Corrosion / Tarnish:

Of metal elements used in combination with organic materials: often the organic material exacerbates the corrosion. Rust, or green copper corrosion products can cause staining of the surrounding organic material.

Crack/Fracture (ceramics/ glass):

A narrow opening between two parts that have split or become broken but are not separated from each other. Cracks may become unstable if subjected to stress/impact damage. The area gives a dull ringing tone when lightly tapped.

Crack (paper):

Fractures caused by internal or external pressure to a surface. No loss is implied. Visible break in the surface, occurring when paper is creased or embossed; sometimes called “crazing” in photographs

Crack – structural (stone):

Inherent in the matrix of the material, a major weakness. In stone this maybe the bedding planes.

Cracks (organics / stone):

Narrow openings between two parts of a material that have split or become broken but may not be separated from each other or suffered loss. Usually used to describe breaks in solid materials such as stone, ceramics and wood. In plastics, refers to splits that follow the grain or direction of manufacture.

Craquelure / crazed surface:

Network of (random) cracks in a surface, e.g. painted surface, usually resulting from the surface drying out. Likely to be stable and not flaking.

Crazing (ceramics / glass):

Occurs as a result of stresses between glaze and underlying body resulting in a fine network of cracks in the glaze. Old crazing tends to be stained and the lines are more obvious while fresh crazing appears as clean cracks through the glaze.

Creases / wrinkles:

Occur when a flat, sheet-like material such as paper or fabric has been folded over on itself leaving a lasting depression or ridge along the line.


Irregular pattern of lines, wrinkles or folds etc. in 2d flexible materials, often clothing or large textiles, barkcloth. Tends to be accidental rather than intentional. Creasing is normally described as heavy or light.


Object material exhibiting loss of cohesion leading to loss of particulate matter when force is applied.

Crystalline deposits:

Not all white crystalline deposits are salt growth, may also be remains of some applied chemicals such as pesticides.

Cupping / elevated edges:

Concavity of islands of paint, leading to protruding or raised edges of the paint flake above the main surface, risk of further deterioration through snagging and catching.

Cupping (paper):

Lifting along the edges of cracks surrounding an island of paint so that the paint surface is bent concavely into the shape of a shallow cup.


Implies damage caused by knife, scissors, or sharp implement, usually the surrounding material in robust condition.