A separation between the fibres of canvas, plant, paper or textile surfaces caused by expansion or contraction of areas under tension. Also used to describe a continuous break in a piece of wood that travels along the direction of the grain. Often caused by the dimensional changes that occur as organic materials expand and contract
Where small pieces of stone flake off or split into chips; usually caused by frost damage.
Fine particulate matter caused by the combustion of wood, paper and other materials; settles on surfaces after fires causing staining and disfiguration. Touching soot-covered surfaces can drive soot into the surface of the object and make it impossible to remove.
Occurs when heat-sensitive materials such as wax, vinyl and some adhesives are warmed – e.g. on a hot day, in direct sunlight or under hot exhibition lights.
The removal of the top layer of a material (e.g. paper) due to physical action – e.g. fibres pulled up by removing a piece of sticky tape from a sheet of paper.
Describes the mirror-like appearance of some black and white photographs, where oxidation has caused silver to migrate to the surface of the emulsion.
An indentation caused by physical damage; the term usually implies that there has been some loss to the original material, e.g. to surface coatings or paints.
Corrosion products (iron oxides) that form on the surface of iron and iron alloys. Rust is not protective and will accelerate the corrosion of the metal until there is no iron left.
Where a sheet material (e.g. paper) has become tightly curled. Rolled materials will often exhibit a “memory” of being rolled, and will be difficult to lay flat. Brittle materials may break on unrolling.
Often called 'sticky tape'. Adhesive tape that adheres to a surface when pressure is applied. The adhesive frequently degrades leaving a brown residue, which stains and makes the paper brittle. Some conservation grade pressure sensitive tapes are available but they are generally not recommended for use on original materials.