Paper Glossary

Acid Free Paper- Paper that contains no free acid.
Air Dry Pulp- Pulp whose moisture content is in equilibrium with the ambient atmosphere.
Acidity- The state of a substance that contains acid. Paper becomes acidic from the ingredients used in its manufacture, from the enviroment or both.
Additive- A mineral, chemical or dye added to pulp and coatings to give it special qualities such as opacity.
Alum- An astringent crystalline substance used in rosin sizing to hold paper fibers together and responsible for introducing acid into the paper.
Archival- A term describing the use and collection of government or corporate documents.
Absorbency- The extent to which a paper will take up and hold a liquid.
Antique- A characteristic low degree of surface finish which typifies certain commercial descriptions of paper.
Airmail Paper- Paper made in the lightest substance consistent with strength and a good surface, for reasons of postage costs.
Art Paper- It is a woodfree coated paper.
Ash Content- The amount of residue when a sample of paper is burned under controlled conditions so that all ignitable matter is removed.
Bamboo Pulp- Pulp obtained by chemical means from the stems of bamboo.
Bagasse Pulp- Pulp obtained from bagasse, the residue after extracting the juice from sugar cane.
Buffering- Aprocess that neutralizes a paper's acidity over time by adding an alkaline substance, like calcium carbonate, at the pulp stage.
Bast Fibers- A group of fibers commonly used in Japanese papermaking, including flax, gampi, hemp, jute and mitsumata.
Bleach- A chlorine solution often used in paper making to whiten.
Beating- The mechanical treatment of fibrous materials in a beater or refiner to modify certain of their characteristics in order to give them the properties necessary for the manufacture of a desired quality of paper.
Binder- The adhesive used to stick the layers of coating together and to the paper or board surface.
Brush Coating- A method of coating a web of paper in which the applied coating slip is distributed and smoothed by means of brushes.
Calendered- Paper which has been smoothed and polished between sets of rollers called a calender.
Caliper- The thickness of paper expressed in thousands of an inch.
Cold Pressed Paper- Mildly textured surface produced by pressing the paper through unheated rollers.
Cast Coated- A method of drying coated paper by contact of the freshly coated surface with highly polished chromium plated heated metal surface.
China Clay- A natural mineral, consisting essentially of hydrated silicate of alumina, used as a filler or as a component in a coating slip.
Cotton- Also referred to as rag or linters, cotton is one of the most commonly plant fibers used in western paper making.
Coated Paper- Material coated on one or both sides with a mixture of china clay, latex and other loadings to fill up surface pits and improve the printing surface.
Couching- The process of transferring partly dried sheets of paper from cloth mold to a felt blanket for further drying.
Chiri- A Japanese term for mulberry bark. Chiri is commonly used to refer to any paper with inclusions of mulberry bark in it.
Deckle- Wood frame resting on or hinged to the edges of the mould that defines the edges of the sheet in handmade paper making.
Dry End- The part of a paper making machine where the paper passes through steam-heated drying cylinders.
Dry Offset- A method of printing from a relief plate without the use of any fountain solution.
Die-Cut Paper- Paper cut made with a special punching blade rather than a conventional rotary blade.
Dimensional Stability- The degree to which a paper will maintain its size and shape when subjected to changes in moisture content and relative humidity.
Embossed Paper- Paper on which a raised or depressed design has been produced by pressure.
Fountain Solution- Water, with additives for application to the lithographic plate on a printing machine.
Filler- A material such as china clay which is added to make paper smoother and increase opacity.
Fibers- The slender, thread like cellulose structures that cohere to form a sheet of paper.
Finishing- The term used to describe the cutting, sorting, trimming and packing of paper.
Felt Finish- Surface characteristics of paper formed at the wet end of a paper machine, using woven wool or synthetic felts with distinctive patterns to create a similar texture in the finish sheets.
Formation- The arrangement of fibers in a sheet of paper; can be seen by holding it up to a light source.
Gloss- It can refer to the reflectivity of paper itself or of the printed result on it.
Gampi- The rarest of the major sources of bast fiber. Bast fiber comes from the gampi tree, found only in the wild. Used in Japanese paper making it produces a smooth, strong sheet.
Half Tone- The representation of tonal gradation by an image composed of dots of varied sizes, the centers of which are equidistant.
Hemp- Not to be confused with cannabis or marijuana, Hemp is an older name for abaca. Related to the banana plant, the leaf fiber is often used in paper making
Handmade Paper- A sheet of paper made individually by hand using a mould and deckle.
Hot Pressed Paper- Smooth, glazed surface produced by pressing the paper through hot rollers after the formation of the sheet.
Internal Sizing- The addition of materials to the stock to increase the resistance of the finished paper to the penetration and spreading of aqueous liquids.
Kozo- The most widely used bast fiber in Japanese paper making. Kozo is a long, tough fiber from the mulberry tree that produces strong absorbent sheets of paper. the most common fiber used in Japanese papermaking. Commonly referred to as paper mulberry.
Laid Paper- Paper with a prominent pattern of ribbed lines.
Linters- A term for pre processed pulp, cotton or wood purchased in sheet form.
Lignin- A component of the cell walls of plants that occurs naturally, along with cellulose. Lignin is largely responsible for the strength and rigidity of plants, but its presence in paper is believed to contribute to chemical degradation
Lightfastness- A speed at which a pigment or colored paper fades in sunlight.
Matt Coated Paper- This paper has calcium carbonate added in its production to make a more satin effect from an art paper.
Mould- A tool used for handmade paper making. A flat screen that filters an even layer of fibers through it to form the sheet.
Mouldmade Paper- High quality paper made on cylinder mould machine.
Machinemade Paper- Paper made on a very rapid running machine called a fourdriner, producing consistent quantities of sheets or rolls.
Mottled Paper- Mottled paper is made by adding some material during the making of the paper to give it a different look.
Mitsumata- A bast fiber used in Japanese papermaking that yields a soft, absorbent and lustrous quality.
Nap- A slight surface texture of some writing suurfaces.
Parchment- Animal skin or lining stretched and prepared as writing or painting surfaces.
Pulp- Any cellulose plant fiber cleaned and beaten into a wet mixture used to form sheets of paper.
Ph- A measure of the hydrogen ion concentration of a water solution and substance, denoting acid or alkaline.
Plate Finish- A smooth surface found on paper that has been run under a calender machine one or more times.
Ply- A single web of paper, used by itself or laminated onto one or more additional webs as it is run through the paper machine.
Rough Paper- A heavily textured paper surface produced by placing wet sheets of paper against textured blankets or air drying.
Rag- Formerly the principal raw material used in the paper making process; often meaning cotton rags. Rag content describes the amount of cotton fiber relative to the total amount of material used in the pulp.
Recycling- Use of recovered waste paper and board by paper mills to produce paper and boards.
Relief- A method of printing ink on paper, using type or images that rise above the surface of the printing plate.
Sizing- The process by which any synthetic substance is added to paper to provide resistance to the absorption of moisture or eliminating ink feathering and bleed through.
Slurring- The smearing or elongation of halftone dots or type and line images at their trailing edges.
Slurry- Watery suspension of pigments, etc…which is used in coating or papermaking.
Tint- A very light or delicate variation of a color.
Tooth- A slightly rough paper which permits acceptance of ink readily.
Uncoated Paper- Paper that has not been coated with any material.
Vellum- A paper surface that is finely textural. Vellum is also used to designate heavy weight, translucent drawing of drafting papers.
Varnish- Thin, protective coating applied to a printed sheet of paper for protection or improved appearance.
Watermark- The translucent design or name easily visible when a sheet is held to the light.
Web- The continuous ribbon of paper in its full width, during any stage of its progress through the paper machine.
Wove Paper- Papers which show no fine "laid" lines running through the sheet when held to the light.
Wet Strength- The strength of a sheet of paper after it is saturated with water.