A
Acid Free (Neutral pH)
Papers that are without acid in the pulp. Acid free papers have a pH of 7.0. If prepared properly, papers made from any fiber can be acid free.
Acid Migration
The transfer of acid from an acidic material to a less acidic or neutral-pH material. Occurs when neutral materials are exposed to atmospheric pollutants or when two paper materials come in contact. Acid can also migrate from adhesives, boards, endpapers, protective tissues, paper covers, acidic art supplies, and memorabilia.
Alum
An astringent crystalline substance used in rosin sizing to hold paper fibers together; responsible for introducing acid into the paper.
Antique
A printing paper with a rough finish but good printing surface, valued in book printing for its high volume characteristics.
Archival Paper
A paper with long-standing qualities, acid free, lignin free, usually with good color retention.
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.
Absorbency
The extent to which a paper will take up and hold a liquid.
Absolute/relative moisture
Absolute moisture the absolute moisture of the air is the maximum amount of water vapour which the air can contain before the excess water is released as dew or frost. Absolute moisture is measured in grams per cubic metre. As the temperature falls the air contains less water in grams at the same relative moisture.To understand why the air may be drier or damper, we can consider why someone's beard becomes frosty on a cold winter day, when the air seems to be dry, while water evaporates when we sit in a damp sauna.
B
Buffering
The neutralizing of acids in paper by adding an alkaline substance (usually calcium carbonate or magnesium carbonate) into the paper pulp. The buffer acts as a protection from the acid in the paper or from pollution in the environment.
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.
Bleach
A chlorine solution often used in paper making to whiten.
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.
Brightness
Brightness is one of the most important characteristics of paper. Very often brightness is held to be the sole measure of quality, but for overall quality the matter is not so simple. For example, opacity generally weakens with an increase in brightness.The appearance of brightness depends on the nature of the light falling on the paper, that is the distribution of the light's wavelength. For this reason comparison of the brightness of different papers must be carried out in the same place or with the same measuring equipment. Brightness is now a days measured with a spectrophotometer which can be used in accordance with different standards (DIN, ISO, SCAN and TAPPI). The same apparatus can be used to determine paper shade and opacity. The best meter for brightness and shade is, however, the human eye.
Bulk
Bulk expresses the specific volume of a material. Bulk is the inverse of density.
/g) bulk = 1 / density = (cm
In the paper trade bulk is a more commonly used measure than density to indicating the "compactness" of paper. Bulk can be calculated by dividing the thickness of a sheet by its basis weight. In some connections, bulk is used to express the thickness of paper or board according to the following equation
bulk x basis weight = thickness
For example
| Bulk | Basis weight | Thickness | ||
| 1.3 | 100 g/m | 130 microns | ||
| 1.6 | 80 g/m | 130 microns |
This is done particularly when choosing bookprinting paper and packaging.
C
Caliper
The thickness of paper expressed in thousands of an inch.
Calendered
Paper which has been smoothed and polished between sets of rollers called a calender.
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.
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.
Cellulose
The chief constituent of the cell walls of all plants. All plants contain tissue that, when properly processed, will yield cellulose. Cotton in its raw state contains about 91% and is the purest form of natural cellulose. Other sources for papermaking include hemp (77%), softwoods & hardwoods (57% to 65%), and kozo (66% to 77%).
Charta Emporetica
In pharmacy etc. charta emporetica was a kind of paper made very soft and porous , used as a filter. It was also used for packing.
Cold Pressed
A paper surface with slight texture produced by pressing the finished sheet between cold cylinders.
Construction Paper
Construction paper or sugar paper is a tougher type of coarse colored paper typically available in large sheets. The texture is slightly rough and the surface is unfinished.
Clothing
Transfer paper is used in textile heat is applied at the one side of the paper to transfer the image on the cloth.
Cotton Linters
Fibers that adhere to cottonseed after ginning. Used as raw material to produce pulp for cotton fiber content papers.
D
Deckle Edge
The feathery edge which is the result of the natural run-off of wet pulp when making handmade and mouldmade paper, or the result of sheets being torn when wet. The edge is simulated in machine made papers by cutting them with a stream of water when still wet.
Dimensional Stability
The degree to which a paper will maintain its size and shape when subjected to changes in moisture content and relative humidity.
Deinking
A process in which most of the ink, filler and other extraneous material is removed from printed and/or unprinted recovered paper. The result is a pulp which can be used, along with varying percentages of wood pulp, in the manufacture of new paper, including printing, writing and office papers as well as tissue.
Digester
A cylindrical or spherical vessel used to treat cellulosic materials with chemicals under elevated pressure and temperature to produce pulp for papermaking.
Density
Density is the specific weight of a material. Lead is denser ) of lead weighs more than a cubic metre of than cottonwool a cubic metre of (m . When the density of a material cottonwool. The density of water is 1000 kg/m is less than that of water, the material will float on the water's surface and will not sink. Paper density expresses how compact the paper is. Paper density is calculated from the basis weight and the thickness as follows
Density ) where w is the basis weight. = w/thickness = (g/cm)
E
Eggshell Finish
Generally refers to a book grade of paper that has a fairly rough finish that resembles the surface of an egg.
Envelope Lining Paper
Tissue paper used to line the inside of matching stationery envelopes. Used for decorative purposes.
F
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.
Felt Side
The top side of the paper, usually recommended for best printing results.
Fiber
The slender, thread-like cellulose structures that cohere to form a sheet of paper.
Filler
A generic term to describe the non-oxidizing clays or minerals added to the pulp at the beater stage to improve paper density.
Finishing
The cutting, sorting, trimming and packing of paper.
Formation
The arrangement of fibers in a sheet of paper; can be seen by holding it up to a light source.
Form bond
A lightweight commodity paper designed primarily for printed business forms. It is usually made from chemical wood and/or mechanical pulps. Important product qualities include good perforating, folding, punching, and manifolding properties. The most common end use for this grade is carbon-interleaved multi-part computer printout paper, which is marginally punched, crossperforated, and fanfolded.
Free Sheet
Paper free of mechanical wood pulp or paper made from pulps having a high freeness (the rate at which water drains from a stock suspension through a wire mesh screen or a perforated plate).
G
Gampi
A bast fiber from the gampi tree used in Japanese papermaking to yield a smooth, strong sheet.
Grain
Direction of fibers in a sheet of paper. Long grain describes fibers running parallel to the longest side of a sheet. short grain running parallel to the short side.
Grams per square meter
The gram weight of a hypothetical square meter of a particular type of paper, a good comparative measure because it does not vary with sheet size.
Grade
(1) A class or level of quality of a paper or pulp which is ranked, or distinguished from other papers or pulps, on the basis of its use, appearance, quality, manufacturing history, raw materials, or a combination of these factors. Some grades have been officially identified and described; others are commonly recognized but lack official definition. (2) With reference to one particular quality, one item (q.v.) differing from another only in size, weight, or grain; e.g., an offset book paper cut grain long is not the same grade as the same paper cut grain short.
Mechanical paper Papers other than newsprint, made with substantial proportions of mechanical pulp, and used for printing or converting.
H
Handmade Paper
Paper made by hand using a mould (a frame covered with a flat, rigid screen or flexible screen). In both cases the mould is covered by a flat frame called a deckle, to contain the run-off of wet pulp, dipped into a vat of wet pulp, shaken to distribute the fibers evenly and drained of its excess water. The wet mat of fibers remaining in the newly formed sheet is then dried against blankets & may be hot pressed, cold pressed, or air dried.
Hot Pressed
A paper surface that is smooth, produced by pressing a finished sheet through hot cylinders.
High Alpha Cellulose
A very pure form of wood pulp which is considered to have the same longevity as cotton or other plant fibers.
Humidity
Paper is a very living material. Variations in humidity and temperature have a great effect on it. Therefore it is important to know how the paper will react to the characteristics of the surrounding air. If the surrounding air is more humid than the paper, the paper fibres absorb the humidity and swell. If the air is dryer than the paper, the paper fibres absorb the humidity and swell. If the air is dryer than the paper, the paper fibre releases its own moisture and shrinks.
I
Index Paper
A heavyweight stock, with a smooth finished used for products such as cards, brochures or any forms needing extra durability.
Intaglio Printing
The intaglio printing process uses a metal plate that has had the image cut into the surface. The sunken image is filled with ink and the surface is wiped clean so only ink is left in the sunken image areas. It is a very specialized process that gives a document a very high quality look. Intaglio is an old printing process but is still used today as one of the best security features on valuable documents.
J
Job Lot
Paper that does not meet specifications of the manufacturer or end user. For some reason it is no longer considered first quality. It may not meet standards or it may also be the overrun from an order. This paper is usable and can generally be purchased at a substantially lower cost than the first quality paper.
Jump Perforation
A partial perforation that runs parallel to the direction that the web is running through the press. Also called a skip perforation.
K
Kozo
The most common fiber used in Japanese papermaking, it comes from the mulberry tree. A long, tough fiber that produces strong, absorbent sheets.
Kraft bag paper
A paper made of sulfate pulp and used in the manufacture of paper bags. It normally has a greater bulk and a rougher surface than the usual kraft wrapping paper.
Kraft wrapping paper
A paper made essentially from wood pulp produced by a modified sulfate pulping process. It is a comparatively coarse paper particularly noted for its strength, and in unbleached grades is primarily used as a wrapper or packaging material. It can be watermarked, striped, or calendered, and it has an acceptable surface for printing. Its natural unbleached color is brown but by the use of semibleached or fully bleached sulfate pulps it can be produced in lighter shades of brown, cream tints, and white. In addition to its use as a wrapping paper, it is converted into such products as grocery bags, envelopes, gummed sealing tape, asphalted papers, multiwall sacks, tire wraps, butcher wraps, waxed paper, coated paper, as well as specialty bags and sacks.
L
Laid Papers
Papers with a "grid" pattern in the sheet, resulting from the pulp resting against wires on the papermaking mould screen. "Laid" lines are closely spaced while "chain" lines are farther apart & run parallel with the grain direction of the sheet, important when folding papers, especially to bookbinders.
Lightfastness
The speed at which a pigment or colored paper fades in sunlight.
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. To a large extent, Lignin can be removed during manufacturing.
Light Weight Coating (LWC)
Light weight, two side coated mechanical reel printing. Paper with a grammage of less than 72 gsm. It is used for magazine, mail-order, catalogues etc.
M
Machinemade Paper
Paper made on a very rapid running machine called a "Fourdrinier", producing consistent quantities of sheets or rolls.
Methylcellulose
A pure adhesive which dries clear. Suitable for archival mounting.
Mitsumata
A bast fiber used in Japanese papermaking that yields a soft, absorbent and lustrous quality.
Mouldmade Paper
Paper made by a slowly rotating machine called a cylinder mould that simulates the hand-papermaking process. Fibers become more randomly intertwined than in machinemade papers, producing a stronger, more flexible sheet or roll.
N
Nap
A slight surface texture of some writing surfaces.
Newsprint
A lightweight paper, made mainly from mechanical wood pulp, engineered to be bright and opaque for the good print contrast needed by newspapers. Newsprint also contains special tensile strength for repeated folding. It does not include printing papers of types generally used for purposes other than newspapers such as mechanical printing papers for catalogs, directories, etc.
O
OCR Paper
Paper that has been manufactured to meet the requirements of the optical character requisition equipment utilized to read and record the characters printed on the paper. Properties of this stock generally include a higher level of brightness for contrast with printed characters, dimensional stability and resistance to curl. It requires stronger fiber bonding to resist picking or surface deterioration from ink. It contains low levels of surface particles and has a high level of resistance to moisture penetration.
Offset Paper
Paper that has been manufactured with properties that make the paper suitable for offset printing. Some of the properties include dimensional stability, resistance to curling, high surface strength a surface free from foreign particles and a high level of resistance to moisture penetration.
Out of Register
When an image is not printing in the exact location that it is suppose to. When printing more than one color, if the colors do not line up properly, they are out of register.
Overruns
The quantity of items produced over the quantity that was originally ordered. Also referred to as any paper spoiled in the process of printing.
P
Parchment
Animal skins or linings stretched and prepared as writing/painting surfaces. Produces a smooth, buttery surface.
Paper Honey Comb
Paper honey comp is a building and packing material. One of the most common uses of paper honey comb is for standard doors inside house. Honeycomb is mass of hexagon al wax cell built by honey bees in the nest. Prism packed comb made of paper instead of wax.
Ply
A single layer of paper. A term used when several sheets of paper are laminated together to form a board.
Plate Finish
A smooth surface found on paper that has been run under a calender machine one or more times.
Pulp
Any cellulose plant fiber cleaned and beaten into a wet mixture used to form sheets of paper.
pH
In chemistry, pH is a measure of the concentration of hydrogen ions in a solution, which is a measure of acidity or alkalinity. The pH scale runs from 0 to 14 and each number indicates a tenfold increase. Seven is pH neutral numbers below 7 indicate increasing acidity, with 1 being the most acid. Numbers above 7 indicate increased alkalinity with 14 being the most alkaline. Paper with a pH below 5 is considered highly acidic. Buffered papers typically have a pH between 8.5 and 9.5.
PVA (Polyvinyl Acetate)
An archival white glue that is stronger than gel medium. It mixes well with gloss medium. Transparent even after many coats and remains water soluble. Mixed with gel it becomes water resistant.
Q
Quadtones
Four halftone images, produced at different screen angles, which were made from the same image and then printed over each other in four different colors.
Quadroplex
A term used to describe two-up printing on a duplex printer. Two pages are printed on each side of the sheet, aligned to produce four pages.
R
Rag
Formerly the principal raw material used in the 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. "Rag content" is not widely used (or is a misnomer) today as more and more high quality paper is made not from rag but from linters .
Rice Paper
A common misnomer used to describe Oriental papers. There are no papers made from rice, although rice starch was traditionally used to size papers made of Kozo (mulberry plant), Gampi, or Mitsumata.
Rough
A heavily textured paper surface produced by placing wet sheets of paper against textured blankets or air drying (or both).
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.
S
Size or Sizing
The process by which gelatin rosin, starch or other synthetic substance is added to paper to provide resistance to the absorption of moisture or eliminating ink feathering and bleed through. Sizing added to the beater or vat of pulp is known as internal sizing. After a sheet is formed, it may be either surface sized (painted or brushed on the surface), or tub sized (immersed in a bath).
Sulphite
Sulphite pulp is produced from the wood of coniferous trees. Wood chips are cooked in calcium bisulphate or sodium sulphite, and bleached, producing fairly long strong fibers. Since the end of the 1860s until recent years, it has been the most widely used pulp in America. In fact, the term"sulphite" has become generic and is still accurately used to describe any paper made from wood, as opposed to papers made from cotton or other fibers. Sulphite pulp is available in a range of grades up to pure alpha cellulose.
Slurring-
The smearing or elongation of halftone dots or type and line images at their trailing edges.
T
Tooth
A very slight surface texture of paper preferred for dry media such as charcoal and pastel.
Tint
A very light or delicate variation of a color.
U
Uncoated Paper
Paper that has been manufactured without the use of coating materials.
Unders
Underruns, the quantity of pieces that a printing run is short of the original order quantity.
V
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.
W
Waterleaf
A paper with little or no sizing. Very absorbent.
Watermark
The translucent design or name easily visible when a sheet is held to the light. A design is sewn onto the papermaking screen with raised wire. When the sheet is formed, the pulp settles in a thinner layer over the wire design.
Web
The continuous ribbon of paper, in its full width, during any stage of its progress through the paper machine.
Wheat Paste
A preferred archival adhesive for book arts.
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.
X
Xerographic Bond
Paper suitable to use for making copies on a photocopier.
Y
Yield
A measure of the square inches of paper per pound.
Z
Z-fold
A paper fold represented by back and forth folds into three panels.
Zig-zag Folding
The fan-folding used on continuous forms to convert roll paper to a continuous flat stack of forms.
