In this glossary are definitions of terms or concepts found on this website that may be unfamiliar to some readers. If you don’t find the information you are looking for in this glossary or in a standard dictionary, here are two additional resources to explore, one for terms used in archives and the other for terms used in museums:
Accessioning: the process of physically and legally transferring historical materials to a repository.
Acid-free (see also Alkaline): Material that is has a pH of 7 or greater. It refers to both pH neutral material, and to alkaline material.
Acidic: Material that has a pH of 1 to 6 is acidic. Acids break down paper at a molecular level. This makes the sheet weaker. Newsprint and wood pulp mat board contain acidic components and should not be used with records, documents, or drawings of value.
Acrylic: A stable plastic that is made into sheets for use as glazing material in framing. Plexiglas© is one brand of acrylic.
Alkaline: Material that has a pH of 8 to 10 is alkaline. This characteristic is recommended for papers and tissues that are used to store records, drawings, or documents. It provides some protection for papers that are acidic and that may become more acidic with the passage of time.
Archival: Of or pertaining to archives. 1. Used by archivists to describe records that have enduring value (see also Historical record). 2. Used by preservation professionals as shorthand for materials with a wide range of characteristics that make them suitable for long term contact with valuable items (see also Archival quality). Unfortunately this term has no precise definition and is sometimes used by vendors to inaccurately enhance the description of a material. When selecting archival materials, look instead for the more precise terms, such as alkaline, buffered, calcium carbonate, acid-free, pH neutral.
Archival quality: 1. Records media that are resistant to deterioration or loss of quality, allowing for a long life expectancy when kept in controlled conditions; 2. Records storage conditions that will not cause harm or reduced life expectancy.
Archival records: See ‘Historical records.’
Archives: a facility that preserves records with historical value; can also refer to a group of archival records.
Archivist: An individual responsible for acquiring, caring for, and providing access to records of enduring value, according to the accepted principles and practices of the profession.
Buffer: In preservation, this term is used synonymously with “alkaline” and “calcium carbonate”. It counteracts acids in paper.
Calcium carbonate: A material that is added to paper or board stock as it is being manufactured to give it an alkaline pH.
Chemically stable: Not prone to deteriorate or to cause damage to valuable materials. Buffered mat board is chemically stable. Newsprint is not.
Compress: Alter a computer file electronically so it takes up less space. 'Compression' is often used to describe the process of compacting and extracting (or decompressing) the information in a file. The digital image formats JPEG and GIF both use compression to minimize file size.
Conservation: 1. The repair or stabilization of materials through chemical or physical treatment to ensure that they survive in their original form as long as possible. – 2. The profession devoted to the preservation of cultural property for the future through examination, documentation, treatment, and preventive care.
Conservator: A professional who carries out the activities of conservation according to the accepted principles and practices of the profession
Convert: To move data to a different format, especially data from an obsolete format to a current format; migration (for example, from audio or videotape to computer files, or from floppy disks to CDs).
Curator: 1. An individual responsible for oversight of a collection or an exhibition. – 2. The administrative head of a museum or collection.
Deed of Gift: A document that transfers legal ownership of materials from the current owner to the repository, establishes conditions governing the transfer of title to the materials, and specifies any restrictions on access and use.
Digital media: Any electronic storage medium that holds digital data, which is currently encoded in seies of 1’s and 0’s.
Digital print: An image captured with a digital camera or scanner and stored as an electronic file.
Digital recordings: A method of recording that converts audio and video signals into a stream of numbers that can be interpreted, modified, and played back by computers and other digital devices.
Electronic records: Data or information that has been captured and fixed for storage and use in an automated system and that requires the use of the system to render it intelligible by a person. 'Electronic records' usually refers to information created and stored in computer systems.
Ephemeral: Not meant to be permanent. Newspapers were meant to carry the news of the day and disposed of once read, unlike books. The preservation of ephemeral materials requires more effort that the preservation of more sturdy materials.
Facsimile: A copy. One could create a facsimile of a newspaper by either photocopying it or by scanning it and printing out the image.
Frame: The wooden, metal, or plastic “collar” that surrounds and holds together the mat, the glazing, and the picture.
Glassine: A very smooth-surfaced paper used to protect the surface of drawings in storage that have crumbly, powdery, or smeary media, such as pastel, charcoal, or chalk.
Glazing: The clear sheet of glass or acrylic (plastic) that protects the surface of the picture. Please see the website for a full discussion of these two options.
Hinge: A small tab of Japanese paper that attaches the artwork to the backing board of the mat. Japanese paper is recommended because it is lightweight yet strong.
Historical record: Materials created or received by a person, family, or organization, public or private, in the conduct of their affairs that are preserved because of the enduring value of the information they contain or as evidence of the functions and responsibilities of their creator. Also known as archival records or permanent records. Also used to refer to the totality of publicly available records in all repositories.
Historical society: Historical societies are non-profit organizations that collect materials usually related to a particular town, city, county, or region. They may collect objects, as a museum does, and/or they may concentrate on archival materials such as papers, photographs, maps, film, video and audio recordings, and electronic files.
Import: In computer applications, the process of incorporating data from an external source into an application.
Interleave/interleaf: A paper or tissue (lightweight paper) that is placed between two documents, drawings, or other media. Interleaf can protect the image surface and allow more than one item to be placed in a folder. It is used to protect powdery media, such as pastel, pencil, or charcoal, or to separate an acidic paper from another paper.
Japanese paper (also mistakenly called “rice” paper): A thin but very strong paper, handmade from the mulberry or kozo plant, which is native to Japan.. It is used by conservators for mending tears. It is recommended for hinging because it is reversible if attached with wheat starch paste, and because it is so thin that it causes no distortion in the artwork.
Kraft paper: A strong paper made from wood pulp by a modified sulfate process. Normally brown, kraft paper can be bleached to tan or white. Commonly used to make grocery bags and for counter rolls.
Laminate: To apply a thin plastic coating to a document to give it additional strength and protect it from the environment. Lamination is generally not considered appropriate for preservation because the plastic may interact with the document over time and because the film is difficult to remove. Lamination differs from encapsulation because the latter covers the document but does not attach the protective film to its surface and is easily removable.
Lignin: A complex polymer that makes cell walls in plants strong and rigid. Lignin left in papers made from wood pulp leads to chemical degradation. Most lignin can be removed from pulps during manufacturing.
Library: a place in which literary, musical, artistic, or reference materials (as books, manuscripts, recordings, or films) are kept for use but not for sale.
“Magnetic album”: Photo albums usually made from a thick paper stock, coated with glue strips for attaching pictures and covered by a plastic cover which also adheres to the glue. These have proven to be very bad for photographs, as the glue is irreversible and will permanently damage the image.
Magnetic cloth: A synthetic cleaning cloth that holds dust through static electricity, not through the use of chemicals.
Magnetic field: A field that surrounds magnetized materials and electric currents. Magnetic fields can cause damage to electronic records.
Mat: A mat is a window cut into a piece of mat board. It surrounds the image of a drawing or print and separates the surface of the artwork from the glazing. The window is attached to a solid backing board. This 2-piece unit is also sometimes called the mat. The drawing or print should be hinged onto the backing board, not taped to the back of the window.
Mat board: The paperboard used to make a mat or mount. See rag mat board and purified wood pulp mat board.
Media: 1) As pertaining to drawings and artwork, it is the material that the image is drawn (or painted, or printed) with. Some examples of media are oil paint, pastel, charcoal, chalk, crayon, and pencil. 2) As pertaining to electronic records, media refers to the physical material that can record information, such as a flashdrive or computer disc; also called "storage medium" or “storage media.”.
Melinex©: A trade name for polyethylene terepthalate. It is manufactured by DuPont.
Migrating adhesive: An adhesive that has aged and in doing so has either sunk into the paper or adhered to an adjacent paper. Many pressure sensitive adhesives migrate. This makes them unsuitable for use on important records and papers.
Migrate (see also Convert): The process of moving data from one information system or storage medium to another to ensure continued access to the information as the system or medium becomes obsolete or degrades over time. Copying information onto the same format storage media without any alteration is generally referred to as refreshing.
Museum: a non-profit, permanent institution that acquires, conserves, researches, communicates and exhibits the tangible and intangible heritage of humanity and its environment for the purposes of education, study and enjoyment. (Definition from the International Council of Museums) Most museums focus their collecting and programs on objects, such as two-dimensional art works or three-dimensional artifacts, for display in exhibits.
Mylar©: A trade name for polyethylene terepthalate. It is manufactured by DuPont.
Open file format: A published specification for storing digital data, usually maintained by a standards organization, which can be used and implemented by anyone, royalty-free. In contrast to open formats, proprietary formats are controlled and defined by private interest
P.A.T.: Photographic Activity Test. This test is carried out by a professional facility on items sold by vendors. A product that has passed the PAT will not scratch the silver emulsion on photographs or cause them to tarnish.
PDF, PDF-A: A file format developed by Adobe Systems that can be used to distribute formatted output, including text and graphics, from a variety of applications to users working on a variety of platforms. PDF/A is a special variant of the PDF developed for long-term preservation of electronic textual documents. PDF/A files can be created with Adobe Acrobat and several other software packages
pH: A measure of acidity or alkalinity. A pH of 7 is neutral. A pH of 1 to 6 is acidic. A pH of 8 to 10 is alkaline.
Photo corners: Paper or stable plastic mounting corners, usually used for photographs but also applicable to other paper items, that allow for display of items in exhibits and in albums without putting adhesives into contact with the actual item.
Polyester: In preservation, the term polyester actually refers to a specific plastic, polyethylene terepthalate. This is one of the three plastics that are recommended for the storage of records and other documents and prints (the others are polyethylene and polypropylene). Technically, the term polyester refers to an entire class of compounds.
Polyethylene: A specific stable plastic that is usually flexible and slightly translucent. It is often made into sleeves to house papers.
Polypropylene: A specific stable plastic that is somewhat stiffer than polyethylene. As film, it ranges from sparkling clear to hazy and is often made into sleeves. As a rigid sheet, it is translucent and is often made into containers such as CD clamshells.
Preservation: 1. The professional discipline of protecting materials by minimizing chemical and physical deterioration and damage to minimize the loss of information and to extend the life of cultural property. – 2. The act of keeping from harm, injury, decay, or destruction.
Pressure sensitive adhesive: Adhesive that sticks to something when it is pressed. Scotch© tape and Post-Its© are well known pressure sensitive adhesives. They are very convenient but are not safe for records and important documents. They can turn brown and lose their stickiness over time. They can sink or migrate into the paper that they are holding together and become impossible to remove without damaging the paper.
Purified wood pulp mat board: A mat board, less expensive than rag mat board, made from wood pulp that has been chemically processed to remove its lignin and has had a calcium carbonate buffer added to it. It is not as strong as rag mat board, but it is as chemically stable and is suitable for long term storage or framing.
PVC: abbr. polyvinyl chloride. PVC film is a clear plastic that can be stretched but is hard to tear. It has been widely used to make pages with pockets to hold photographs, slides, baseball cards, coins, and other small items. However, PVC outgases chemicals that can damage adjacent materials. It has the distinctive smell of a beach ball or a shower curtain.
Rag mat board: Mat board that is made from very strong cotton fiber. It is the most durable and expensive type of mat board. It can be buffered or not buffered.
Reformat: To create a copy with a format or structure different from the original, especially for preservation or access. For example, a newspaper article could be photocopied onto alkaline paper. In principle, an item can be reformatted without any effect on its content, but in practice such reformatting may be imperfect, with a resulting loss of meaning.
Repository: An institution that collects historical and other materials. There are several kinds of repositories, including archives, libraries, and museums. A historical society may have an archives, library, or ,museum as part of its organization. A local library may have a local history room. A college library may have an archives or a special collections unit.
Reversible: In preservation, “reversible” means readily removable without causing damage. For example, hinges attached with wheat starch paste are reversible. Hinges attached with pressure-sensitive tapes will cause damage if removed and are not reversible.
Rich Text Format (RTF): A file format, developed by Microsoft, that allows you exchange text files between different word processors in different operating systems.
Wheat starch paste: Paste made from wheat flour with the protein component (gluten) removed. This helps the paste to be smoother. Traditionally it is cooked fresh each week, but it can be purchased in small, ready-to-use-portions.
Ultraviolet light: The portion of the spectrum with a wavelength shorter than that of violet light. Also called “UV” or “black” light. Shorter wavelengths of light cause more fading of colors and damage to paper. An item framed with UV-filtering glazing is protected from the most damaging component of light, though it will still fade if displayed permanently.
