Glossary

  • ACID

    A substance, usually water soluble that releases hydrogen ions in solution. It has a pH less than 7 and turns blue litmus paper red. Acids are corrosive.

    Acid PH

    Acid PH Litmus Paper

  • ACID-FREE

    Widely-used term to describe products that are free of acids at the time of manufacture or sale. However, such products may break down over time and become acidic, and should not necessarily be considered suitable for conservation. Choose products described as archival quality and/or lignin free.

  • ALKALI

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    Alkali PH on Litmus Paper

    A substance with a pH above 7 and turns red litmus paper blue. It has an ability to neutralise acids and forms salts with them. Highly alkaline materials are corrosive.

  • ARCHIVAL QUALITY

    A widely used term to describe materials that are suitable for use for the long term storage, or archiving, of materials.

  • CELLAIR™

    A brand name for a sheet foam, used by museums for packing and storage.

    Cellair™

    Cellair™

  • CHEMICAL DETERIORATION

    Deterioration caused by chemical change within a substance.

  • CORROSION

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    Corrosion in copper

    An example of chemical deterioration, usually indicates the gradual deterioration of a metal or alloy. Patina, tarnishing and rust are results of corrosion.

  • D-RINGS

    Conservation-standard hanging device for paintings and 2-D artworks, comprising a metal loop (the ‘D’) that is screwed onto the back of the work’s frame.

  • DACRON®

    Type of wadding fabric, sometimes used for quilting.

    Dacron®

    Dacron®

  • ELECTROMAGNETIC SPECTRUM

    The compete range of electromagnetic radiation from gamma rays (shortest waves) to radio waves (longest waves).

    Roll over the grey box to see visible light

  • EXTERNAL WALL

    The interior surface of a building’s outer wall. The temperature of these walls change as the environment outside changes. See also internal wall.

  • FUMIGANT

    A substance that gives off fumes, especially one used to kill pests.

  • INFRARED RADIATION

    Radiation produced with a wavelength in the range of 750 nanometres to 1 mm, between the light and radio waves on the electromagnetic spectrum.
    See Electromagnetic Spectrum.

  • INORGANIC MATERIAL

    Chemicals or substances, which are not primarily based on the elements carbon, for example stone, clay and metals.

    A range of objects made from inorganic materials. Labelled on photo: jade, porcelain, earthenware, glass, metals…

    A range of objects made from inorganic materials. Labelled on photo: jade, porcelain, earthenware, glass, metals…

  • INTEGRATED PEST MANAGEMENT (IPM)

    A sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimises economic, health and environmental risks.

  • INTERNAL WALL

    Walls which divide the building into rooms. These rooms are buffered from environmental changes. See also external wall.

  • LARVAE

    When an insect egg hatches, larvae is born. The larvae is the feeding phase of the insect, which is essential to complete metamorphosis into the adult insect (moth, beetle). They are worm-like or grub-like in appearance.

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    Insect Larvae in wood

  • LIGNIN

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    Diagram of Lignin within the plant cell structure

    A cellulose-related substance that lines the vegetable cells of wood, giving rigidity to the material.

  • LUMEN

    Unit of illumination, defined as the amount of light striking a surface at a given distance from a source of a given intensity.

  • LUX

    Unit of illumination, defined as one lumen per square metre.

  • MICROCLIMATE

    An enclosed space (such as a display case or storage box) which provides a climate within it that differs from the surrounding external environment.

    A display case is an example of a microclimate.

    A display case is an example of a microclimate.

  • MYLAR™

    A brand name for a type of polyester. Often used in conservation as protective sheets or enclosures.

    Mylar™

    Mylar™

  • OFF-GAS

    The release of fumes or vapours by a material into its surrounding environment. This can occur continuously from some materials (eg some woods), or during the drying or curing of other materials (such as paints, varnishes and adhesives).

  • ORGANIC MATERIAL

    Material that is primarily based on the elements carbon and hydrogen. This includes most materials deriving from animals and plants, such as paper, textiles, furniture, and some man-made materials such as plastics.

    A range of objects made from organic materials. Labelled cotton textile, silk textile, straw, emu egg, feathers, plastic.

    A range of objects made from organic materials. Labelled cotton textile, silk textile, straw, emu egg, feathers, plastic.

  • pH

    A measure of the acidity, alkalinity or neutrality of a solution or substance.

  • PHOTOCHEMICAL DETERIORATION

    Cumulative damage to organic materials caused by exposure to visible light or ultraviolet radiation. Damage includes discolouration, fading, weakening and embrittling of the material.

    Effects of photochemical deterioration to a book

    Effects of photochemical deterioration to a book

  • POLYETHYLENE

    A polymer of ethylene used to make plastic containers etc. In conservation, commonly used in clear sheet form, available in various thicknesses. Often used to wrap or protect objects.

    Polyethylene sheeting

    Polyethylene sheeting

  • POLYMER

    A term used in organic chemistry to describe a compound formed by two or more molecules of the same substance to produce a new compound.

  • PREVENTIVE CONSERVATION

    A non-invasive method of conservation that aims to thwart or prevent the deterioration of cultural material. It aims to provide the cultural object with a stable environment so that deterioration or damage is minimised.

  • RELATIVE HUMIDITY (RH)

    The ratio of the amount of water vapour in the air at a given temperature with the total amount air can hold at the same temperature, expressed as a percentage.

  • REMEDIAL CONSERVATION

    An interventive method of conservation that includes the repair and treatment of cultural material, aimed at slowing the process of deterioration and rectifying damage that has occurred. Only a qualified conservator should undertake remedial conservation.

  • SIGNIFICANCE ASSESSMENT

    The process of studying and understanding the meanings and values of objects and collections. Significance assessment is a practical and effective process that helps you to clearly articulate the value and meaning of objects and collections, and make sound judgements and good decisions about conserving, interpreting and managing them, now and into the future.

  • STRAINER

    Fixed timber framework on which the canvas of a painting is stretched.

    A strainer. Note that the joints are fixed and not expandable.

    A strainer. Note that the joints are fixed and not expandable.

  • STRETCHER

    Timber framework on which the canvas of a painting is stretched. Unlike a strainer, a stretcher’s corners are not fixed so they can be ‘keyed out’ to take up slackness in the canvas.

    A stretcher. Note that the corners can be expanded by knocking in the keys to make stretcher larger.

    A stretcher. Note that the corners can be expanded by knocking in the keys to make stretcher larger.

  • ULTRAVIOLET RADIATION

    Radiation produced with wavelengths from 5-400 nanometers, beyond the violet region of the visible light spectrum.
    See Electromagnetic Spectrum.