Damage to objects caused by mechanical rather than chemical means and resulting in cracks, chips, splits, tears, dents, punctures, breaks, scratches, scuffs and abrasions, as well as soiling, wear and tear, warping, shrinkage, separation of layers of composite materials, graffiti and insect attack.
A scale of measurement ranging from 0-14 for identifying the level of acidity of solutions - the hydrogen ion (H+) concentration. Pure water has a pH of 7 which is considered neutral, whereas acidic solutions fall below 7 and alkaline solutions have pH values exceeding 7.
Usually used to describe a thin layer of paint that is becoming detached from a surface and curling back on itself. May also be used to describe the appearance of veneered surfaces that are delaminating.
A fungal disease which attacks seasoned timbers, often causing the wood to be reduced to a dry, crumbly texture or to structurally collapse.
A concave, convex or twisting change of form, used to describe stiff organic materials that have become misshapen, such as paper, card, plant fibres and wood.
Overall change in the colour of a material, usually to a darker, more yellow or brown appearance. May be caused by light damage or by exposure to acidic substances.
Particulate material which has settled on the surface of an object. Contributes to corrosion, staining and abrasion of surfaces.
Where a portion of an object has become separated from the main, due to physical damage such as breaks or tears, or by failure of an adhesive or another attachment method.
Occurs when a material loses its strength and creates an area of collapse. Can also occur where an external impact or pressure causes a depression or indentation.
Separation of individual layers of a laminated material from one another – e.g. the emulsion layer from a glass plate negative; layers within a sheet of board.
