Glossary

A

A4 — used as the standard cut paper size measurement outside of the United States. Measures 8.3 x 11.7 inches (210 x 297 mm) and is equivalent to the standard U.S. 8.5 x 11 inch paper

Acid-free paper — paper which does not contain free acid and is used primarily for archival purposes

AFPA — acronym for American Forest and Paper Association

Aging — the deterioration or alteration of a paper's characteristics over the course of time

ANSI — acronym for American National Standards Institute

Antique finish — a rough, uncoated paper finish that implies a bulky sheet

ASTM — acronym for American Society for Testing and Materials

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B

Back-roll mark — a small recurring area of excessive coating due to a depressed area on the coater's backing roll.

Baggy roll — a roll that has a non-uniform draw across the web resulting in slack or tight sections.

Base stock — also known as raw stock or base sheet

paper used as the base sheet for coating or further converting

Basis weight — In the United States, the basis weight is the weight in pounds of a ream (500 sheets) of paper determined by a basic size. However, the basis weight size varies by grade of paper. Throughout the world it is the grammage or grams per square meter.

Beater — a large container in which pulp is refined and mixed with other paper ingredients

Binder — material found in coating or inks that holds the materials together or holds it to the paper surface.

Binder specks — a variation in ink receptivity caused by non-uniform binder distribution. A coated paper defect that results in a grainy or textured appearance on the coated surface.

Blade coating — a primary method of coating using a flexible knife blade to apply a smooth and level coating to the paper surface,

Blade mark — also known as a blade scratch or blade streak. Caused by a foreign piece of material caught under the coating blade, resulting in a scratch or streak that will cause the paper surface to appear less opaque under a low angle light.

Blanket — a rubber surface material covering the printing cylinder that transfers the ink from the plate to the paper.

Bleed — an image that extends beyond the trim edge of a sheet of paper.

Blinding — a condition in offset lithography where the plate has lost ink receptivity and fails to produce an image.

Blistering — a defect in the paper surface due to rapid expansion of moisture. Usually cause by high drying temperatures, high paper moisture or low internal bond strength.

Blocking — when several sheets or layers of paper stick together.

Bond paper — originally used for printing bonds or stock certificates is now a term applied to writing or business papers. Known for strength and good writing characteristics such as letterhead and correspondence papers.

Book paper — A term for paper primarily used by the book publishing industry. Generally has a slightly higher opacity than the equivalent weight bond paper.

Brightness — the measure of the amount of light reflected from the paper.

Broke — reprocessed scrap paper from any process in the paper mill. Most broke is gathered before it is finished and returned to the furnish for reprocessing into sellable paper.

Buckle — an area of the roll where the paper is overly compressed and creates a buckle when it is wrapped.

Bulk — a measurement of the density of specific grade of paper in relation to the basis weight. In book binding it is a measurement of the thickness.

Burst — a rupture through the web of paper. Can be caused by a tension burst from an area of low and high caliper or where the tension exceeds the strength of the paper.

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C

C1S — paper that is coated on one-side only

C2S — paper that is coated on two sides of the paper

Calcium carbonate — a white pigment that is used in the furnish or coating process of the paper.

Calendering — the process of passing the paper through metal rolls,leveling and smoothing the surfacewhile adding gloss to the finish of the paper.See also supercalender.

Calender marks — Marks left on the paper through the calendaring process.Can include blackening(due to excessive roll heat) or barring(due to a damaged calendar roll).

Caliper — The thickness of one sheet of paper usually measured in thousandths of an inch.

Cast - coated paper — a coated paper that is dried against a rotating chrome surfacewhile wet to generate a highly polished gloss surface.

Cellulose fibers — the primary ingredient in making paper.The fibrous raw material that results from breaking down the wood or plant materials through pulping or bleaching processes.

Chalking — a condition where the ink rubs off of the paper like a powder due to improper drying or coating,improperly prepared ink or paper that is too absorbent.

Chemical pulp — the treatment of groundwood chips with a chemical process(usually including the use of sulfites and sulfates) tobreak down the lignin.

Chlorine - free — a term used to describe the pulp or paper bleaching process.Can include elemental chlorine - free(ECF) or totally chlorine - free(TCF) processes.

Chest — an industry term to describe a storage tank or holding areafor pulp,furnish,water,or other materials used in paper making.

Cigar — a small cylindrical web defect of pulp or tissue pulling out of the web.

Clay — a filler pigment that can be used in the paper making process or in the coating process to aid with opacity and smoothness

Coated paper — paper with a surface coating ranging from dull to glossy that aids in the ink - holdout,smoothness and levelness of the paper

Coating — The application of water based pigments and binders that enhance the printing or optical properties of the paper.

Coating lump — a random piece of dried coating that has been redeposited onto the web of paper.

Coating mottle — a slight mottle created during the calendaring process due to a non - uniform base sheet or coating process.

Coating pits — microscopic holes in the coating air bubbles in the coating process

Coating splash — random spots of excess coating

Cockle — a rippling effect in the paper due to drying with minimum tension.It can be created as a desired effect or can be undesired result of improper drying.

Color progression — The order in which different color inks are laid down on the paper.

Conditioning — bringing the paper to the same atmospheric conditions as in the pressroom over time.The goal is to have the relative humidity of the pressroom to match the paper to minimize curl and other defects.

Conversion coated(off - machine coated) — paper that is coated after it is removed from the paper machine in a separate process.

Core — rigid cardboard tubes that are uniform in diameter usedfor winding paper web onto a roll.

Core damage — crushed core) - a core that has been compressed or impacted so that it is no longer round.

Core waste — the amount of paper that is left on a roll of paper after printing

Corrugating — see fluting

Couch marks — defects or shadows which appear in a regular pattern on the paper.Often caused by the irregular removal of water on the wet end of the paper mimicking the pattern of the equipment that removes the water.

Cover paper — A wide variety of heavy papers that are usedfor the outside covers of books, magazines or other published pieces.

Crack — a fissure of the paper caused bybreak in the surface of the coating during printing or other converting processes.

Cracked edge — a small tear at the edge of the web paper

Crease — a defect resulting from a fold over in the web paper process

Cross - machine direction — The direction across the grain of the paper at right angles to the machine direction

Curl — a deformation in the paper which causes it to roll in the form of a cylinder

curl can be caused by variations in relative humidity or differences in structure or coating between the two sides of the paper.

Cut size paper — refers to any paper that is cut to 17" x 22" in size or less, usually referring to business size paper.

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D

Dampening solution — see fountain solution

Dandy roll — a wire covered roll used to impress patterns onto a wet web sheet

used primarilyfor creating a woven laid pattern or watermarks.

Deciduous — leafy hardwood trees such as aspen or maple that loose their leaves in the fall.

Deckle — The width of the web sheet between the deckle edges or the straps at the wet end of the paper machine that control the width of the paper web.

Deckle edge — The feathered,untrimmed edge of the paper web

De - inking — The process of removing inks from recycled papers so that it can be reused in the paper making process

Densitometer — a tool used to measure the density of colored ink or print density

Desensitization — in lithography,applying a gum solution to the plate making the non - image areas on a plate repellant to ink

Digester — a large container where wood is pulped or"cooked" using chemicals, heat and pressure.

Digital printing — the ability to print without plates using digital information sent directly from the pre - press systems.

Direct printing — the process of printing directly from the plate to the substrate without the use of an offset blanket to transfer the ink from plate to paper

examples include — letterpress,gravure or lithography

Dirt — any foreign material that is unintentionally embedded into the sheet of paper

Doctor blade — a blade used to remove ink,coating or papermaking debris from the surface of the paper roll.

Dog ear — a small fold that occurs on the corner of the paper during the papermaking or converting process.

Dot gain — an increase in size of a printed dot on the paper making the image appear darker.

Double coated — paper that has been coated twice on the same side

Doubling — The appearance of a shadow or blurred image due to a sheet mis - feed or paper being out of registerwhile printing.

Drawdown — the application of a thin film of ink using a spatula or blade to measure the ink 's color shade and characteristics.

Dry end — the final portion of the paper machine

the end of the machine where the paper is dried.

Dryers — Cylinders,blowers,radiant heat or other equipment used in the papermaking or printing process to assist the paper or ink drying

an substance added to the ink to speed up the ink drying process(also spelled driers)

Dull finish — also known as a matte finish

a finish with little or no gloss

Dust — small particles of paper,fibers or coating materials that are found in a finished roll of paper found at the edges of a skid

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E

ECF — environmental chlorine-free

Embossed — paper with a raised or depressed surface to simulate leather or wood

Emulsification — the mixing of two distinct solutions that do not mix such as a fountain solution which is water based and ink which is oil based.

Enamel — a glossy coated paper

Engraving — recessed printing where the images is cut or etched below the printing surface and filled with ink

EPA — acronymfor the Environmental Protection Agency

Equivalent weights — a mathematical equation used to compare paper weights with different sizes and basis weights

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F

Fan-out — In web offset printing it is the result of the increase in the web width after each blanket impression and could result in mis-register

Feeder — The section of the press that separates sheets or controls the web roll as it is fed into the pressfor printing

Felt — The fabric used to cover the rollers to support the paper as it moves from the wire through a portion of the dryer section

Felt mark — an imperfection in the paper caused by a damaged felt

Felt side — the top side,or side opposite the wire side of the web paper - usually considered the smoother side of the paper

Fill — the maximum width of paper that can be made on a given paper machine

Fine paper — a general term used to describe printing,writing or cover papers

Finish — the condition of a paper surface when it has been put through the complete paper making process - a high finish is hard and smoothwhile a low finish is rough

Flexography — the use of rubber,or flexible,relief plates and fast drying inks

Flow — the ability of an ink to spread over the press rollers

Fluting — waves in web offset prints that run parallel to the press direction,or with the grain,often caused by excessive ink coverage or tension in the web during ink drying

Flying pastor — a device used to splice rolls of paper together during the converting or printing process without having to stop the equipment

Foam spots — Small spots on the finished paper that are a result of foam in wet end of the paper machine or in the coating

Folding endurance — a test to measure a paper 's durability and ability to withstand multiple folding before experiencing failure

Formation — The uniformity of the distribution of fibers throughout the paper,which could influence the appearance,strength and mottle of the paper

Fountain solution — A combination of chemicals in water used in the lithographic printing process to keep the non - image areas on a plate moist and from accepting ink

Freeness — the rate with which water drains from the pulp furnish

Free sheet — Paper which is free,or contains minimal traces,of groundwood pulp

Furnish — a mixture of ingredients that is used to make paper,usually about 1 % solid material,fiber and fillers and 99 % water

Fuzz — fibers that project from the surface of a sheet of paper

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G

Ghosting — An unwanted, secondary image that appears on a print

Gloss — the properties of a paper which causes it to reflect light specularly which result in its shininess or mirror - like surface

Grain or grain direction — refers to the machine direction of the paper as it was made on the paper machine

Grain - long — when the grain direction is parallel to the long dimension of the sheet

Grain - short — when the grain direction is parallel to the short dimension of the sheet

Groundwood paper — a term used to describe papers that contain groundwood or mechanical pulp

Groundwood pulp — pulp that is made up of mechanically ground wood and still contains the lignin material,also known as mechanical pulp

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H

Hard-sized — paper that is heavily sized to increase water resistance

opposite of slack-sized

Headbox — the first section of the paper machine where furnish is mixed and then distributed evenly along the plastic wire mesh

Hickey — a print defect,usually a light area formed around a dark circle,caused by foreign particles in the ink adhering to the blanket or plate and interfering with the transfer of ink

Hold - out — the abilityfor a paper to resist ink absorption,creating a higher gloss finish

Hygroexpansivity — the expansion or contraction of paper due to a change in moisture content,usually caused by a change in the relative humidity

Hysteresis — the abilityfor two pieces of paper to have different moisture content at equilibrium conditions based on the previous relative humidity exposure

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I

Ink absorption — the rate at which ink is absorbed into the paper substrate after deposition from the plate or blanket

Ink hold - out — see hold - out

Internal bond strength — the measure of the forces with which fibers are bonded to each other within a sheet of paper

Internal sizing — sizing additives that are added to the slurry or furnish to distribute it evenly throughout the paper

ISO — Acronymfor International Standards Organization

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J

Job lot — paper rejected because of defects or is produced as an overrun

Jumbo roll — a roll of paper directly from the paper machine that has not been slit or rewoundfor shipping

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K

Knife coating — see blade coating

Kraft paper — paper made from the sulfate pulp

Kraft pulp — pulp made from the sulfate process,primarily a mixture of sodium hydroxide and sodium sulfide,creating a strong pulp

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L

Lignin — a natural occurring glue in wood that helps to hold the cellulose fibers together

Lint — foreign material that appears on the paper surface,unlike fuzz,it is not attached to the surface

Lithography — Any process in which the printing is done from a plane surface - conventionally done through a photochemical process where the image area carries ink and the non - image area carries water

Loose core — the looseness of the winding of paper web at or near the core of the roll

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M

M weight — the weight in pounds of 1000 sheets of paper of a given basis weight and dimension

Machine finish — the finish that is applied on the paper machine

Matte finish — very little or no gloss on the paper surface as a result of coating without,or with very limited,supercalendering

Mechanical pulp — pulp prepared through mechanical rather than chemical methods,see groundwood pulp

Mil — a measurement of thickness equal to one thousandths of an inch

Moisture content — the percentage of water in pulp,paper or paperboard

Mottle — a random,uneven appearance of the surface of the paper

non - uniform distribution or appearance of ink

Mullen test — test used to determine the bursting or rupture strength of paper

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N

Newsprint — uncoated printing paper, usually made from mechanical wood pulp

Nip — the contact point between two rolls of paper

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O

OCR — acronym for Optical Character Recognition

Off-machine — a process such as supercalendering or coating that is done separate from the paper machine

Offset — indirect printing used primarily in lithography where the ink is transferred from the plate to a blanket and then from blanket to paper

Offset book — uncoated papers that are sized internally and on the surface to withstand the offset process

One-side coating — paper coated on only one-side, such as labels

On-machine — a process such as supercalendering or coating that is done as part of the paper machine

Opacity — the property of paper that minimizes the ability to see show through (printing on underlying sheets) or print through (print on the back side of the sheet)

Optical brightener — fluorescent dyes added to paper to enhance the visual brightness

Optical density — the intensity of color or the printed image

OSHA — acronym for Occupational Safety and Health Administration

Overruns — paper that is manufactured exceeding what is ordered, usually acceptable within certain tolerances based on the size of the order

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P

Paper — the term that describes the process of intertwining cellulose fibers and other binding agents on a wire form and subsequently formed and dried to create a sheet or web used for writing, printing, packaging, etc.

Paster — see splice

PG — acronym for Pressure Groundwood a form of mechanical pulp

pH — the measurement of the acidity or alkaline properties on a scale of 1 - 14, with 0 - 7 being acidic and 7 - 14 being alkaline and a pH of 7 considered neutral

Pick — the lifting or release of material from the paper surface during printing

Pigments — clay, minerals and other materials that are added to coatings to enhance properties of the paper

Piling — the buildup of material from paper on the calendar roll or printing blanket

Plate — also known as printing plate, a plate carrying an image or typeset page for use in making multiple copies of that image

Point — a measurement of thickness, one thousandths of an inch, see caliper or mil

Porosity — a measure of the porous nature of the paper determined by the passage of air through the sheet

Post consumer fiber or post consumer waste - also known as recovered fiber, fiber collected from finished product after it has gone through the consumer lifecyclePress run — the quantity of prints for a given job

Printability — the ability of paper to give the truest reproduction of the original image at the maximum efficiency, a combination of print runnability and print quality

Process printing — or process color, the use of semi-transparent inks to build color by overprinting one color on top of another using subtractive primary ink colors

Psychrometer — an instrument used to determine relative humidity

Pulp — the result of wood (or other plant) processing

the primary raw material to make paper

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Q

There are no entries for "Q".

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R

Rattle — also called snap, the noise that results from shaking or crumpling a piece of paper caused by a combination of the sheet stiffness and bulk

Ream — a sheet count of commonly 500 sheets of paper (can vary slightly based on basis weight)

Recovered fiber — see post consumer fiber

Recyclable paper — paper that can be easily recovered to make new paper

Recycled content paper — paper that is made from some percentage of recovered materials

Recycled paper — paper made from recycled fiber

Reel — a roll of paper off of the paper machine, before it is slit down into shipping rolls

Reflectance — the amount of light reflected by paper

Relative humidity — the percentage of the amount of moisture in the air relative to the moisture it can hold without saturation

Retention — a percentage of the amount of filler in the finished sheet relative to what was added into the furnish

Re-winder — a machine used to take finished rolls from the paper machine and slit them and re-roll them into smaller rolls

Roll — can be defined as a shipping roll—a roll that is slit and ready to ship to the customer, or a jumbo roll, or reel—a roll that is just off of the paper machine prior to slitting

Roll curl — see curl

Roll number — a number used by the mill to identify date of manufacture, roll position and machines used for production

Roll position — the position of a shipping roll relative to its position from the front edge of the paper machine

Rosin — a component used in sizing of paper to help aid in water resistance

Roughness — the degree of high or low spots on a sheet of paper relative to its surface

Runnability — paper runnability refers to the characteristics of a paper which affect its own production, printing or converting. Print runnability refers to the characteristics of the paper which allows it to be run through a press without causing operating difficulties or slowdown

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S

Scale — a piece of foreign material that is deposited on the paper web after it is formed

Score — the process of creating a crease in the paper to allow it to fold more easily

Scrap-in-roll — paper waste from slitting or converting that is wound into the roll

Scuffing — the raising of fibers on the surface of the paper as a result of rubbing against another sheet of paper or a rough surface

Sheeter — a converting machine used to produce sheets of paper from a roll

Sheet fed — a press where the paper is processed as sheets as opposed to a web-fed press

Shipping roll — a finished roll that is slit and ready to ship to a customer

Show through — see opacity

Signature — a printed flat sheet that is to be folded into a complete unit or document

Sizing — the process of adding materials to the furnish or to the paper surface to provide water or ink holdout properties to the paper

Slice — a small opening in the headbox where the furnish is sprayed out to form the paper web along the forming wire

Slime — small clusters of bacteria that can become imbedded in the paper on the wet end of the paper machine

Slitter — a small circular blade that cuts web rolls in the machine direction into smaller width rolls

Sludge — the accumulation of a thick, viscous coating that builds up on the blade at the nip which could occasionally break through the blade and stick to the surface of the paper

Smoothness — the opposite of roughness

the surface texture of the paper

Snap — see rattle

Soda pulping — a pulping process that uses sodium hydroxide and high temperature and pressure

Spectrophometer — a tool that measures the relative intensity of color or difference in color

Splice — two ends of the web that are overlapped and adhered with adhesive or tape to create a continuous roll

Starch — a material used in the papermaking process, both at the wet end and in the coating to improve the characteristics of the paper

Stretch — the amount of give a sheet of paper has when under tension

Stuck web — the condition where a tacky material gets between two layers of paper and causes them to stick together

Supercalendering — The process of passing paper between rolls to create a highly polished finish, see calendering

Surface defect — a visible defect or foreign matter on the surface of the paper

Surface strength — the ability of the paper surface to resist picking during the printing process

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T

TAPPI — acronym for Technical Association of the Pulp and Paper Industry

TCF — acronym for totally chlorine-free

Tear strength — a test which determines the force required to tear paper

Telescoped roll — a misaligned roll with one edge concave and another convex

Tensile — the force required to pull a piece of paper to failure

Thermomechanical pulp — a pulping process that utilizes heat and pressure to aid in the mechanical pulping process

Thickness — see caliper

Titanium dioxide — a mineral used in the furnish and/or coating of paper to improve the opacity or brightness of the paper

Trim — the maximum width of the paper roll that can be made on a particular paper machine

Turned edge — a piece of the web edge that is folded over, also known as a turnover

Turnover — see turned edge

Twin-wire machine — a paper machine that utilizes two wires to sandwich the furnish leaving the headbox allowing the pulp slurry to drain faster and creating paper with less two-sidedness

Two-sidedness — the difference between two sides of the paper, which can be seen in shade, texture or finish

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U

Under run — opposite of an overrun, paper that is manufactured in a quantity that is less than what is specified

Upsized — paper in which no sizing has been added

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V

Varnish — a protective coating applied to a printed piece, which can have a variety of finishes

Vellum finish — a relatively rough finish for fast ink penetration

Viscosity — the resistance of a fluid to flow

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W

Water-marked paper — a visual defect appearing as a light spot on the paper due to water droplets on the web roll

Web — a continuous sheet of paper

Web break — a break of a web a paper when passing through a paper machine, a printing press or a converting machine

Web press — a printing press that runs using rolls of web paper

Web tension — the amount of tension applied to the web paper in the machine direction

Wet end — the front end of the paper machine (headbox, wire and roller presses) where the water and furnish are distributed onto the wire

Wet strength — the amount of strength a paper retains when exposed to water

White water — the water that is drawn off of the furnish from the wet end of the paper machine, usually reused in the paper making process

Wire — or forming wire, a fabric woven out of monofilament plastics to create a screen to separate the fibers and filler from the water in the furnish

Wire-mark — a mark left on the paper web from the formation wire

Wire-side — the side of the paper web that come in contact with the forming wire during manufacture

With-the-grain — parallel to the grain or the machine direction of the paper

Wrinkle — a crease in the paper web

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X

There are no entries for "X".

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Y

Yellowing — the deterioration and discoloration of a sheet of paper due to exposure to air, light or heat

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Z

There are no entries for "Z".

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