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Glossary

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a* (ClE Starlab)
Refers to the system used to describe and measure color. a* indicates redness, positive value, and greenness, a negative value.

A4A
Symbol for standard metric "cut-size" paper that is nominally 20 x 30 cm or exactly 2 10 x 297 mm; used as the European (and other parts of the world) standard in place of 8 1/1 x 11 inches; is an ISO standard.

ABRASIVE PAPERS
Papers covered on one or two sides with abrasive powder.

ABSORBENCY
Property of pulp, paper or board to retain materials it contacts such as liquid, gas and solid substances. 1) In paper, the property that causes it to take up liquids or vapors in contact with it. 2) In optics, the partial absorption of light as it passes through a transparent or translucent material.

ABSORBENT PAPERS
Examples include duplicator, blotting, filter papers, drying royal, matrix paper and toweling.

ACCELERATED AGING
A method of predicting the long-term aging characteristics of paper by exposing it to an elevated temperature and controlled environment of dry and moist heat for a specific time and then measuring its strength loss.

ACID FREE
A paper having no acidity and no residual acid producing chemicals. Papers manufactured to a pH of higher than 7.0 (neutral). These papers may also have a built in alkaline reserve to counteract the harmful effects of aging in an acidic environment.

ACID SIZING
See alum.

ADDITIVE
Also see primary colors. A mineral, chemical or dye added to pulp and coatings to give it special qualities such as opacity.

ADHESIVE BOUND
Book binding technique which uses glue or hot melt glue to hold each page or signature together and into the cover of the book.

AF & PA
American Forest & Paper Association. An organization that coordinates the many different needs of the broad based paper and paper board industry, including statistical information relating to production, consumption, exports and imports of paper and to raw materials energy, governmental regulations, forecasts, environmental matters and transportation.

AGAINST THE GRAIN
Folding or feeding paper at right angles to the grain direction of the paper.

AGING
The deterioration of paper properties over time. Sunlight and heat accelerate loss of strength and brightness.

AIR DRY
Term applied to any pulp and paper sample that has a moisture content in equilibrium with the surrounding atmospheric conditions. Air-dry pulps are assumed to contain 10% moisture.

AIRLAID
A paper manufacturing process in which fibers are carried and formed to the structure of paper by air rather than water as in traditional papermaking.

ALKALINE FILLERS
Fillers that increase an alkaline reaction in water or which react with acid. Calcium Carbonate is the most common alkaline filler.

ALKALINE RESERVE
The presence of a component e.g. (calcium carbonate) put in paper at a level sufficient enough to neutralize the harmful effects of an acidic environment. ANSI Specifications require a minimum of 2% Alkaline Reserve.

ALKALINE SIZING
Also called neutral or acid free sizing. Incorporation of internal sizing agents and alkaline fillers in the papermaking ingredients to produce papers whose pH is above 7.0 at the point of sheet formation. Synthetic resins are added to the furnish of the paper machine to impart water resistance to paper. Unlike the acid sizing system, alkaline sizing does not use high concentrations of alum to set the size. Common internal synthetic sizing materials are abbreviated as AKD (for Alkyl Ketene Dimer) or ASA (for Alkenyl Succinic Anhydride). An advantage of alkaline sizing is better "permanence" (archival properties).

ALKYD RESIN
Synthetic drying oils made by chemical reaction of various organic acids. See drying oils.

ALUM
An astringent crystalline substance, aluminum sulfate, used in rosin sizing to hold paper fibers together; responsible for introducing acid into the paper. Alum can also be used as a release agent on the paper machine to prevent wet webs from sticking to turning rolls or as a minor additive for alkaline sizing, imparting no pH change.

ANGLE BARS
See turning bars.

ANSI
American National Standards Institute, a nationally recognized coordinating group whose functions are to identify and fulfill the needs for standards. In addition, they act as the interface between government and private sector and between the U.S. and international bodies on the matter of standards.

ANTI-OFFSET SPRAY
In printing, a material (usually dry starch particles) sprayed on to the wet ink film surface to prevent set-off.

ANTIOXIDANTS
Agents which retard the action of oxygen in drying oils (chemical drying), and other substances subject to oxidation.

ANTIQUE FINISH
A very rough uncoated paper finish, obtained on the paper machine with little wet pressing or machine calendering; can also serve as a prefix to other finishes, implying a rougher than usual finish, such as antiquevellum.

ANTIQUE PAPER
Book paper that has a natural rough finish but good printing surface, valued in book printing for its high volume characteristics. The finish is rougher than eggshell finishes but slightly smoother than those designated as extra bulk grades.

ANTI-SKINNING AGENTS
Materials which retard the skin formation on the surface of a drying oil or printing ink; as an example, skin formation can develop when a can of oil based paint is left open, with a resultant drying on the surface and liquid paint still below the "skin."

API
See AFPA.

ARCHIVAL PAPER
A paper with long-standing qualities, acid free, lignin free, usually with good color retention. Paper that is alkaline and won't deteriorate over time. Archival papers must meet national standards for performance: they must be acid free and alkaline with a pH of 7.5 to 8.5; include 2% calcium carbonate as an alkaline reserve; and not contain any ground wood or unbleached wood fiber. The expected life of archival paper is more than 100 years.

ART WORK
Original materials, including the illustrations, lettering, charts, color blocks, etc. which are to be reproduced in a printed piece.

ASH
The inorganic pigment (mineral) residue after complete combustion (burning off) the organics (cellulose fiber for example) from a sheet of paper; used as a test to determine the filler content of the paper.

ASTM
Abbreviation for "American Society for Testing and Materials," which develops and publishes consensus standards, in many fields.

AUTOMATIC DENSITY CONTROL
An automatic toning control system where the toner layer deposited on the paper is controlled by the copier/ printer.

AZURE
The light blue color used in the nomenclature of "laid" and "wove" papers.


 
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