| Definition | ||
|---|---|---|
| ABSORBENCY | The ability of a paper or board to take up and retain liquid, gas or solids so that one substance disappears. | |
| ACCELERATED AGING | Simulated aging of paper by exposure of paper to a hostile environment, such as some types of radiation, elevated temperature (in dry or moist air) or chemical attach over a period of hours, days or weeks. | |
| ACID FREE PAPER | Paper that does not contain any free acid. They may be used for archival purpose or for wrapping articles. | |
| ADHESIVE | Moisture proof adhesive : An adhesive that forms a barrier to moisture or water when applied in a continuous film and that retains its strength in contact with water. Moisture-resistant adhesive : An adhesive, which forms a bond that retains its strength at high humidity or in contact with water. Pressure-Sensitive adhesive : An adhesive that requires only briefly applied pressure at room temperature for adherence to a clean surface. | |
| AEROGRAMME | A single sheet paper, letter form, folded and gummed on three sides. Bears international pre printed air postage and the word "aerogramme" Intended for airmail correspondence to other countries. | |
| AIR DRY MOISTURE CONTENT (AD) | The percentage loss in weight of paper specimen when dried to constant weight in a room or chamber whose ambient air is maintained at 23*C, 50%RH. Air dry moisture content of a Wood Pulp: The " % air dry" equals the "%over-dry" divided by 0.90. Distinct from Oven-dry moisture contents. | |
| AIR KNIFE COATING | A Method of coating using an air-knife which acts on the principle of a Doctor blade and uses a thin, flat jet of air for removing the excess coating from a wet, freshly coated web of paper. | |
| ALKALINE PAPER | Paper having pH values greater than 7 made by an alkaline manufacturing process. | |
| ANILOX (Anilox Roller, Screen Roller) | A knurled, etched or engraved roller used in conjunction with a doctoring device to meter low viscosity printing inks to a printing plate. Used traditionally in flexographic printing. | |
| ANTI RUST PAPER | Paper which has the property of protecting the surfaces of ferrous metals against rust. | |
| ANTI TARNISH PAPER | Paper in which certain substances have been incorporated to make it capable of protecting bright metallic surfaces against tarnishing. | |
| ANTIQUE PAPER | Printing paper having good bulk and opacity with rough or matte surface. | |
| ART PAPER / BOARD | Paper/Pulp Board coated on both sides after manufacture with material containing adhesive , Kaolin etc , to give a surface suitable for fine screen half tone work. | |
| ASH CONTENT | The inorganic residue obtained by igniting a specimen of pulp, paper or other cellulosic material in such a way that the combustible and volatile compounds are removed. The ash content is usually expressed as the percentage of such residue based on the weight of the test specimen. The test must be specified as air-dry or oven-dry ash. | |
| AZURE LAID PAPER | A laid paper usually blue in colour having a good writing surface. | |
| Definition | |
|---|---|
| BAGASSE | The fibre left over after extracting sugar from sugarcane. |
| BAMBOO | A grass yielding a fibre used for papermaking. |
| BAR CODE | A binary code representing characters by sets of parallel bars of varying thickness, separation and vertical position that are read optically by transverse scanning. |
| BAROGRAPH PAPERS | Red thin paper coated on one side with a white wax, so that the needle of the barograph leaves a red line on a white ground, sold in rolls and coils and to suit the type of barograph. |
| BASE PAPER | A term covering a number of papers used as the base for abrasive plastics, coating , tracing and dyeing dry abrasives. Very strong manila base for glass paper and garnet while for glass paper and garnet while for wet abrasive, such as carborundium, high wet strength types are needed, often containing glycerin to help make the paper malleable. red thin paper coated on one side with a white wax, so that the needle of the barograph leaves a red line on a white ground, sold in rolls and coils and to suit the type of barograph. |
| BASIS WEIGHT | The weight in pounds of a ream of paper. Its metric counterpart is GRAMMAGE, where mass per unit area is expressed in units of grams per square meter. |
| BIBLE PAPER | Thin white paper opaque heavily loaded, used for printing bibles. Not suitable for pen and ink, because of its absorbency. |
| BINDER MIGRATION | Coated paper defect where specks give a grainy or textured appearance to the coated surface. Detectable by ink wipe, print test or light iodine burnout. |
| BIOCIDE | A biological control chemical such as fungicide or a bactericide used in paper making. |
| BLADE COATING | A method of coating which utilizes a flexible blade set at an adjustable angle against a web of paper supported by a soft, usually rubber covered, backing roll. |
| BLADE SCRATCH / STREAK | Fine hair like indentation running along the MD in the coating surface. It usually appears less opaque than the general coated area when viewed by transmitted light, lighter than UV light and darker after a K & N ink wipe. |
| BLANKET (OFFSET BLANKET) | The blanket is a rubber covering on an offset printing cylinder, that is used to transfer ink from the printing plate to the paper. |
| BLISTER | Defect on a paper surface often shaped like a human blister . It is due to Delamination of a limited portion of paper without breaking either surface. Coating / Headset blister : Round or oval blister due to coating separating from its base stock. In Headset offset, it occurs in heavily inked areas, due to the dryer heat. Ply separation blister: Ply or layer or paperboard separating for short distances in an irregular manner. Most commonly found in cylinder boards. |
| BLOCKING | Layers of paper adhering firmly together. |
| BOND PAPER | Bond paper is paper used for letterheads, many printing purposes and for plain paper photocopying. The name 'bond ' was originally given to a paper, which was used for printing bonds, stock certificates etc. Important characteristics are finish, strength, and freeness from fuzz, rigidity and traditionally good pen-and-ink writing characteristics. |
| BONDING STRENGTH | The Strength of paper or board to withstand layer-to-layer separation. It is the force with which a coating or film adheres to the surface of a sheet. |
| BOOK | A set of paper pages bound into a volume, where the pages may be printed, written blank or combination. The book comprises the body , a spine, a cover and inside each cover may be a flyleaf. a) Hard cover: A book, which has a stiff cover that may be reinforced with paperboard and covered with cloth. b) Soft cover: A book, which is covered with a protective and glossy coating over the cover, printing. |
| BOOK PAPER | A general term used to define a class of papers used by the book publishing industry; most commonly used for the book text paper but also for book cover paper. Book bulk, Bulk index or inversely as bulking number (pages per inch). |
| BREAKING LENGTH | A measurement of intrinsic Tensile strength of paper, i.e. the tensile strength of paper that is corrected for basis weight. It is the calculated limiting length of a strip of paperboard of any uniform width, beyond which, if such a strip were suspended by one end, it would break by its own weight. It is expressed in units of Km, with the paper's mass understood to be under terrestrial gravitation. Usually it is measured in both machine (MD) and cross (CD) directions. |
| BRIGHTNESS | A measure of the amount of light reflected by a paper at a wavelength of 457 +/- 5 mm. Printers, publishers, sellers refer to brightness which may be approximately by various photometers such as Photo volt, Aleph, GE Brightness, Hunter Lab. They all give somewhat different readings for brightness. Distinct from Whiteness for which a total spectro -photometric reflectance curve is required; whiteness is approximated by the CIE colour-value systems. |
| BRISTOL | A stiff heavy paper whose caliper ranges upwards from 0.006" and which includes bogus, folding, index, printing and wedding Bristol, Bristol covers, postcard and coated postcard. |
| BRITTLENESS | That property of paper whose causes it to break or fail when deformed such as by binding, converting, finishing, folding and handling. Factors, which contribute to brittleness , are composition, moisture, drying and aging. |
| BROKE | Paper that is to be reprocessed from any part of a paper mill. The term originates, when the paper web broke on the paper machine and the resultant mess of scrap paper was gathered and repulped. |
| BRUSH FINISH | An especially high polish given to paper. It is obtained by running the dried or partially dried coated paper over a revolving drum provided with six or more rapidly revolving cylinder brushes which contact the coated surface of the sheet. |
| BULK | Volume per unit weight of a sheet of paper. Bulk index: Bulk index is bulk calculated from single sheet caliper and air-dry basis weight; metric units are cm3/g. The reciprocal of Density. Book Bulk: The overall thickness in mm of a given number of sheets; it is a term useful to book publisher's for managing the paper thickness and number of pages in the book and the final thickness of the book. |
| BURNOUT | The loss of colour during drying. |
| BURNT PAPER | Paper, which has been discoloured and is brittle, but otherwise intact. |
| Definition | |
|---|---|
| CALENDER | A device for smoothening, glazing, caliper reduction and leveling of the surface of the paper to improve the finish and reduce the printing roughness of the paper. Machine Calender: A set of highly polished cast-iron rolls, resting one on the other in a vertical bank at the dry end of the paper machine. Super calender: A set of alternating polished steel and composition rolls resting one on the other in a vertical bank , capable of producing a more uniform smoothness and gloss than a machine calender; thus used to produce a smoother, glossier and denser sheet; usually off-machine. Soft nip calender: An on - machine device consisting of two or more pairs of steel and composition rolls; it is designed to achieve much of the quality of a Supercalender, with much of the production advantage of being on machine, but without the severe operating difficulties of an on-machine Supercalender. |
| CALENDER BARRING / Marks | Dull irregularly shaped bands across the web imparted at the calender, seen when viewed by low angle light. |
| CALENDER BLACKENING | Coverage of the web or streaks of the web or streaks of the web glazed translucent spots. Due to excessive Calender roll heat, calender pressure, and uneven moisture. |
| CALIPER (Thickness) | The average thickness of a single sheet as determined by measuring the thickness of different sheets and averaging the results. |
| CARBON PAPER | Dense tissue papers coated usually with formulas of oil, dye (pigment) and wax. Double - coated carbon (Full Carbon): A carbon paper that is coated on both sides. One-time carbon: A carbon paper intended to be used once as opposed to many time or multiple-use carbon paper. Processed Carbon: Carbon paper which has been sprocket hole punched and perforated before being collated in to the form sets. |
| CARBONLESS PAPER | Paper stock specially treated or coated to provide copies without the use of interleaved carbon. The copy process required mechanical pressure such as from writing or typing and sometimes a chemical reaction. Transfer carbon less: carbon less requiring the contact of two chemically interactive surfaces. Three grades of carbon less paper are made: 1. CB-Coated back 2. CF-Coated front 3. CFB-Coated front and back Self-contained carbon less: Carbon less with both chemically interactive coatings (CB & CF) on one sheet. |
| CARD BOARD | A range of various boards such as pulp board, paste board, bristol board, ivory board, art board, chromo board in the form of a coherent sheet or web used for printing, packing, decorating etc. |
| CARRIER | A substrate that carries an image, data, functional coating, security device etc. |
| CAST-COATED PAPER | Paper or board with a particularly high gloss. This is obtained not by calendering, but by rolling the moist or specially moistened printing material with a chrome-plated drying cylinder polished to high gloss. Cast-coated papers have a shiny mirrored surface |
| CHALKING (Powdering) | A condition where in rubs off a print, as would chalk, after the normal drying period, it usually occurs on coated paper and when normal drying period. |
| CHLORINE FREE | ECF(Elemental chlorine-free): A bleaching that doesn't use chlorine gas. TCF (Totally Chlorine Free): Bleaching without using chlorine or chlorine compounds. TCF paper is made with TCF pulp and recycled TCF paper. |
| CIE COLOUR-VALUE | A set of three colour values (CIE or Hunter) used to designate colour of paper, especially of white and near-white paper. Provision is made for reporting results in one of two scales: -Hunter L, a, b, colour scale (LAB-values) initiated in 1958 -CIE L *.a* ,b* colour scale (CIELAB or LAB star-values) initiated in 1976 (Where a, a* are measures of redness (+) to greenness (-); b, b* of yellow ness (+) to blueness (-); and L, L* is the magnitude upwards on the black (0%) to white (100%) scale) |
| CMP | Acronym for chemi-mechanical pulp. |
| CMYK (cyan, magenta, yellow, black) | The color model usually employed in printing technology which uses the basic colors cyan, magenta and yellow. Black is used to ensure a visually satisfying black tone. |
| COATED PAPER | Paper with an outer layer of coating applied to one or both sides. The coating may be added while the paper is still moving through the paper making machine or after it comes off the machine. Coated papers are available in a variety of finishes like gloss, dull and matt. They tend to have good ink holdout and minimal dot gain which can be especially important for recreating sharp, bright images, black and white halftones, and four-color process images. Chromo paper: Includes woodpulp or woodfree stocks coated on one side (C1S). Chromo paper is used mainly to make labels, wrappings, and cover paper. Art printing paper: A premium-grade stock coated on both sides (C2S), preferable for the high-quality reproduction of color prints. |
| COATING DEFECT | Applicator roll streaks (films split pattern): Defective coating pattern left in a coated surface by cavitation from film splitting during roll coating. Orange peel: When the film-split pattern is uniform over the surface, the roughness of the pattern is somewhat like the outer surface of an orange peel. Coating Band: Heavily coated region of 3 mm or more width extending in machine direction. may be associated with a wet streak at the coater. Coating colour variation: Non uniformity of the coating due to variation in the composition or to a non-uniform layer of the coating colour applied to the paper. Coating colour spot: Small area incompletely coated. May be caused by undispersed components of coating. Uncalendered coating lump: A translucent, discoloured, shiny, hard, brittle spot in the web caused by calendering or supercalendering an un-calendered coating lump. Coating mottle: A small-scale variation of glass of a coated Calender sheet, which can be detected by viewing the surface in specular reflection. A good-coated sheet has relatively uniform glass after calendering. However, if by reason of a poorly formed base sheet or other variable the coated sheet is not uniform the high spots are compressed much more than the low spots in calendering and hence develop a mottle. Coating Pick: The lifting of coating particles from the base sheet during calendering or printing. Coating piling: Blanket piling caused by loose particle partially bonded, coating loosened by the dampening solution due to insufficient water resistance. Coating pits (pinholes, Micro-pits): Microscopic holes in the coating. Due to micro air bubbles in the coating colour. Coating skip: Irregularly shaped areas, devoid of coating. Coating splash: Random spots of excess coating on the coated surface. Coating streak: Broad indentations to the coating surface 3-6 mm wider. Colour Lump: Impressed mark on paper caused by a defect, which appears on the Calender rolls. |
| Coating pick (Flaking) | The removal or lifting of coating particles from the base sheet or from another coating layer during calendering or printing, so that voids or craters are visible at the coating failure. |
| COATING WEIGHT | The grammage of a coating layer, expressed in g/m2 coating per side. |
| COCKLE (Crinkle) | The formation of ripples, bulges or warped spots out of the plane of the sheet caused by uneven moisture, tension during drying. |
| COLOUR COPIERS | Printing by imaging systems that are fed imaging information as digital date from pre-press systems. |
| COLOUR MATCH | Colour quality when there is no significant difference in colour hue between two samples when viewed under standard illumination. |
| COLOUR SEPARATION | Process of separating each of the three primary colours of an original by optically filtering the image. |
| COMPOSITION | The arrangement, efficiency of space and artistic value of printed matter. |
| COMPUTERISED COMPOSITION | A method of preparing copy by computer rather than manually. |
| CONDITIONING OF PAPER | Laboratory conditioning: The exposure or seasoning of paper to accurately controlled and specified atmospheric conditions in the test laboratory, so that its moisture content is in equilibrium with the surrounding atmosphere. Pressroom conditioning: It is now common to condition pressrooms to 45% RH in order to have the pressroom RH in equilibrium with the paper RH and hence to minimize Curl and associated feed holes. |
| COPIER (Copy Machine) | Equipment for automatically making separate copies of graphic matter from plain paper originals. |
| COPY PAPERS | Class of papers normally used for office copiers, e.g. Xerox, bond and stencil duplicating (mimeograph): a number of more specialized papers are blueprint & diazo. |
| CORE | Rigid tubes used as a spool for winding a paper web into a paper roll. |
| CORE BURNOUT | Mechanical damage to the ends of a core which has resulted from the core chucks tearing into the core ends or to slippage of the chucks inside the ends of the core. |
| CORE PLUG | Thick disc placed inside a core to prevent core crushing during handling. |
| CORE SLIPPAGE | Displacement of the core from its intended position relative to the rolled paper. Axial displacement gives a Telescoped roll. Rotational displacement may cause a loose core. |
| CORE WASTE | The amount of paper left on the core or stub roll after printing the paper. |
| CORRESPONDENCE ENVELOPE | A flat case, rectangular in shape and generally made from one sheet of paper. This sheet is so folded as to provide a plain front and back consisting of four overlapping flaps. Generally three flaps are stuck together, the fourth which may be gummed or run-un-gummed, serving as a closure. |
| CORRUGATED BOARD | A composite paper product made by adhering Linerboard to both sides of a web of corrugated medium on a Corrugator. |
| CORRUGATING MEDIUM | A paperboard made usually from semichemical wood pulp or reclaimed fibre on a cylinder or Fourdrinier paper machine; it is corrugated to form corrugated medium which is used as is, but mainly for the fluted part of corrugated board and single facer. |
| CORRUGATOR (Corrugating Machine) | A process machine that continuously fed webs of corrugating medium and linerboard, which flutes the medium and pastes the liner to it in order to make corrugated products. |
| COVER PAPER | A general term applied to a variety of papers used for outside covers of catalogues, booklets and similar pieces. |
| CRACK (Cracking) | A defect in coated paper caused by the separation of the coating layer on formation of fissures in the surface of the coating due to printing or other converting process. Crack at fold: Fissures in the crease when any paper is folded along a fold line. More prevalent when the paper has been overdried. In boards it may occur along score-folds even though the scoring has been done to minimize cracking at the fold. The term is also applied when coatings crack without fibre failure during a folding operation. |
| CREASE | Deformation remaining from a fold over. CD wrinkles: Fold over of a web in the cross machine direction, giving a crease running in the machine direction. Blade crease: A crease essentially in the machine direction devoid of coating in the creased area. Calender Crease: Usually a sharp crease caused by passage through the Calender of a crease or of a fold generated at the Calender; often cut through. Smoothed crease: A flattened-out crease running mainly in the machine direction. Can occur at the wet press section, dryer (dryer wrinkles), size press, winder or sheeter. |
| CREPING | The operation of crinkling a sheet of paper to increase its stretch and softness. |
| CROSS-MACHINE DIRECTION | That direction in the plane of a web or sheet of paper at right angles to the machine direction. |
| CRUSHED CORE (Collapsed Core) | A core within a roll of paper, which has collapsed radially, or the end is crushed axially from excessive thrust loads. Damage is due to hard impact received during handling & transit. |
| CRUSHED ROLL | Defective roll as a result of stacking rolls on end in an excessively high pile, which in turn causes the lower ends of the lower rolls to fail in the axial direction. |
| CTMP | Acronym for chemi thermo mechanical pulp. |
| CURL | Deformation of sheet of paper which tends to roll into the form of a cylinder. The axis may be either in the machine direction, cross direction or diagonal. The paper may be curled towards the wire-like or the felt side. Wet curl: Curl resulting from the application of water to the paper surface . Atmospheric curl (Dry curl): Curl that is the result of the exchange of water vapour between paper and air of higher or lower relative humidity. Mechanical Curl: Curl that is the result of mechanical stresses in the paper, other than that of swelling or shrinkage due to moisture changes. |
| CUT | Rupture of sheet in a defined region, not extending to sever the sheet into two pieces. Blade cut: A straight sharp cur parallel to the direction of web travel. Blister cut: A cut caused by a fold-over of a blistered paper or board, which is creased and cut in the Calender stack. Calender cut: A straight sharp `Blister cut' with a glazed edge, running for a short distance at an angle to the direction of web travel, induced at the Calender stack. Cockle cut: A Blister cut caused by severe cockles. Dry cut: A Calender cut which is 90-120 cm (3-4Ft) in length with no evidence of pucker-wrinkles. Fibre cut: A short, straight, fairly smooth randomly located cut caused by passage through the Calender of an oversized fibre or shive imbedded in the web of paper. Hair cut: A sharp, smooth cut having no definite length or direction, caused by an animal hair or synthetic fibre. Shive cut: Similar to a Fibre cut, but caused by a shive. Slitter cut: `Blade cut' caused by a raised slitter working loose and riding on the web. Sliver cut: A type of `Fibre cut' but caused by wood silver. Winder cut: A cut caused by a winder crack. |
| CUTTER DUST | Small loose particles of paper which chip out of the edges of a sheet of papers as it is cut by the chopping blade on a sheeter. |
| Definition | |
|---|---|
| DAISY WHEEL PRINTING | Impact relief printing usually used for office typing, either a direct mounting on a typewriter or a separate printer for use from word processor input. |
| DAMPENING | The process of keeping the non-image areas of lithographic plates to be ink repellent by applying aqueous Fountain solution to the plate from the Dampening system. |
| DANDY ROLL | A skeleton cylinder covered with a woven wire cloth, or with an arrangement of fine longitudinal wires, crossed at close intervals by heavier circumferential wires. The former structure produces wove and the latter, laid paper. The dandy roll is one method of applying watermarks to paper while wet. |
| DE-INKED PULP | A paper pulp prepared by a combination of mechanical disintegration and chemical treatment of the recycled paper, which makes possible the removal of most of the ink. |
| DE-INKING | The process of ink removal during paper recycling. |
| DECKLE | The straps or boards on the wet end of a paper machine which prevent the fibre suspension from over-flowing the sides and which determine the width of the web of paper that can be made on any given machine. The actual width of the web between the deckle edges. The total width of rolls being deckled together in one parent reel of paper on the paper machine. |
| DECKLE EDGE | The untrimmed featheredge of a sheet of paper formed where the pulp flows against the deckle. |
| DEFOAMER | Chemical added to a liquid to reduce or eliminate tendencies for the liquid to foam. |
| DELAMINATION | A rupture of a sheet of paper through the plane of the sheet, not necessarily breaking either surface. |
| DENSITOMETER | A user-friendly photometer that measures print density directly. It also measures tone values in terms of print density. |
| DENSITY | Mass density: Weight per unit volume of paper, obtained by dividing basis weight by caliper, in g/cm2. Print density: The colour depth (optical density) of a printed image. It may be measured directly by a user-friendly optical meter. |
| DIGITAL PRINTING | Printing by imaging systems that are fed imaging information as digital data from pre-press systems. Computer to-plate Systems: Use printing plates or other images carriers that do not require intermediate films. Computer-to-print (Plateless): Systems that produce reproductions directly on the substrate without the need for intermediate films or plates. Electronic printers: Electrophotographic printers , for black or single colour, used for short-run variable information and on-demand book publishing. Colour copiers: Usually Electrophotographic printers, for spot or four colour process printing, used for making one or several copies of spot or four colour process subjects. Electronic printing systems: Electrophotographic, magnetographic, monographic, field effect, ink jet or thermal transfers printing. For One-colour, four colour process or upto six-colour printing. Used for some degree of variable information, on-demand. Examples of use are direct mail, temporary product labels for trade shows, billboard posters and the like. |
| DIMENSIONAL STABILITY | Ability of a paper or board to retain its dimensions and its shape despite changes in its moisture or mechanical stressing. Moisture changes are caused by differences in ambient humidity from the internal relative humidity of the paper. |
| DIRT | Small flecks of foreign material which have a colour in contrasts to that of the paper, and a combined size and contrast that is large enough to be aesthetically displeasing under normal viewing conditions. |
| DOCTOR BLADE | A blade running across the surface of a roll in order to scrap the surface free of ink, coating or papermaking debris. |
| DOCUMENT | A carrier containing a representation of stored information , such as a form, punched card, magnetic tape, computer disc/diskette or compact disc. |
| DOT MATRIX PRINTING | Impact printing where each character is made up by a pattern of dots, usually made dot by dot, synchronized by computer control. The print head strikes against a ribbon against the paper. |
| DOUBLING | The unintentional printing of two images slightly out of register. |
| DPI | Acronym for dots per inch. |
| DUPLICATING STENCIL PAPER | Paper for the preparation of a Stencil duplicating master. It is a thin, strong, lightweight paper made from long-fibred stock, suitably impregnated or coated such as with oil. |
| DUPLICATOR | Machine for making copies with the aid of a specially prepared duplicating master. Includes machines for Spirit duplicating, stencil duplicating |
| DUST | Small loose particles of paper, coating or foreign material may arise at calendering, slitting and sheeting trimming. |
| DWELL (Dwell Time) | The length of time that two surfaces are in contact e.g. the length of time the ductor roller is in contact with the fountain roller. In-heat-set web offset, dwell is the length of time that the paper web takes to go through the press drier. |
| DYELINE | A process for producing copies employing translucent masters, copy paper treated |
| Definition | |
|---|---|
| ELECTROPHOTOGRAPHY (Electrostatic Copyin | A process (such as xerography) which uses either an intermediate photosensitive plate or drum or a coated take-off sheet which can be electrically charged to attract an imaging agent (toner)) to only the charged areas of the intermediary or to the take-off copy. The image may be fused by heat, pressure or by use of blinders in a liquid toner. |
| EMBOSSED FINISH | Paper with a raised or depressed surface resembling wood, cloth, leather or other pattern. |
| ENAMEL PAPER | A glossy coated paper. |
| EXPOSURE | The steps in photographic processes during which light produces the image on the light sensitive coating. |
| EXTENDER | A blend of pigments of an organic nature used to impart transparency, opacity or working qualities to printing ink. |
| Definition | |
|---|---|
| FANNING | Momentary separation of the press sheets by hand riffling so that fresh air is allowed to sweep over the surface of each sheet. |
| FASCIMILE | Exact copy or likeness; perfect reproduction.The transmission of graphics including pictures by wire or radio and it's duplication. |
| FDA | Acronym for Food and Drug Administration, USA. |
| FEEDER | The section of a press, which separates the sheets and feeds them into position for printing. |
| FELT | A continuous broad porous belt used on the paper machine, traditionally made of wool but frequently of a combination of two or more of the fibres like wool, cotton, and synthetic fibres. |
| FELT SIDE | The topside of the sheet is traditional Fourdrinier paper manufacturing, when this is the smoother side of the paper for printing. |
| FINE PAPER | A board term including printing, writing, copy and cover papers, as distinguished from newsprint, ground wood specialties, paper board and functional papers. |
| FINISH | The finish of a sheet of paper denotes the condition of its surface. A high finish refers to a smooth, hard surface. A low finish refers to a relatively rough, toothy surface. |
| FINISHING OF PAPER | The off-machine operation on paper that prepare it for shipping to the customer especially, slitting, cutting, trimming, sorting, counting, and wrapping of paper. |
| FISH EYE | Round, transparent spot in the coated surface of coated paper or board, which may be caused by excess defoamer of an oil-base type. |
| FLEXOGRAPHY (Flexo) | A method of rotary Relief printing using flexible plates and fast drying inks. The use of resilient rubber or photopolymer relief plates for letter plates for letterpress printing and special inks by an Anilox roll that dry mainly by absorption and evaporation. |
| FLUFF | European term for both of Lint & dust. It consists mainly of individual fibres, particles of fillers, particles of sizing agents. |
| FLUORESCENCE | A property of Fluorescent dyes, also called optical brightness which often added to paper to enhance paper's whiteness or brightness to the eye in normal lighting. |
| FLUTING | Corrugated sheet forming the cushioning layer in corrugated fiberboard. |
| FOLD | Term used to describe how sheets are folded; single fold, double fold, centerfold, and gatefold. |
| FOLDING BOXBOARD | Thin board between 0.25 and 1.1 mm thick suitable for making cartons. It is also known as 'Carton Board'. |
| FOLDING ENDURANCE | The resistance of paper to multiple folding; a measure of paper durability. |
| FORMAT | The size, shape and general arrangement of printed work. |
| FOUNTAIN SOLUTION (Dampening Solution) | In Lithography, water based chemical solution used to dampen the place and keep non-image areas from accepting ink. Traditionally contained gum Arabic, acid and defoamer. |
| FREE (Wood- Free) | Description for pulp or paper that contains nil or minimal mechanical wood pulp. |
| FREENESS | The rate at which water drains from the slurry of pulp on the forming section of a paper machine. Canadian standard freeness (CSF): The rate, at which water drains from a pad of pulp, measured under exacting test conditions. |
| FURNISH | The mixture of various materials that are blended in the stock suspension from which paper or board is made. The chief constituents are the fibrous material (pulp), wet-strength additives & fillers. |
| Definition | |
|---|---|
| GHOSTING (Ghost image) | A secondly unwanted image in a print. It has variations in ink density. |
| GLASSINE | Paper obtained by dampening and supercalendering paper, which is made from highly hydration-beaten pulp. It is very smooth and glossy on both sides and has resistance to the passage of oils grease, and odours. |
| GLAZED | Paper with high gloss or polish, applied to the surface either during the process of manufacture or after the paper is produced, by various methods such as friction glazing, calendering, plating or drying on a Yankee drier. |
| GLAZED IMITATION PARCHMENT | A strong glazed paper made from cellulose pulp. The term, particularly it's abbreviation (GIP) is normally used for paper made from bleached pulp only. |
| GLOSS | The property of a surface which causes it to reflect light specularly, e.g. like a mirror, and which is responsible for its shiny or lustrous appearance. For most printing papers, specular gloss is usually measures at 75* which is the angle between a line normal to the surface of the specimen and the direction of reflected and incident light. Instruments used to measure this property are called glarimeters or gloss meters. |
| GLOSS MOTTLE | Mottle that is characterized by variation in gloss over a paper or over a print surface. |
| GRAIN | Grain, as applied to paper, refers to the machine direction in which the sheet was made on the paper machine. |
| GRAIN LONG | Grain-Long paper: Paper cut with the grain parallel to the long side of the sheet. Grain-Long printing: Printing of paper in a sheet-fed press with the grain parallel to the axis of the press cylinder. |
| GRAIN SHORT | Grain short paper: Paper cut with the grain parallel to the short side of the sheet. Grain Short printing: Printing of paper in a sheet-fed press or copies with the grain or machine direction perpendicular to the axis of the cylinder. |
| GRAMMAGE | The mass of a unit area of paper or board determined by the standard method of test; it is expressed in g/m2. |
| GRAPHIC ARTS | The fine and applied arts of representation, decoration, and writing or printing on flat surfaces together with the techniques and crafts associated with them. |
| GRAVURE | Gravure Printing: A intaglio printing process in which a low viscosity ink is transferred from recessed image cells in the printing plate onto Gravure paper. Sheet-Fed Gravure: Direct Gravure printing using a flat plate and flatbed press. Rotogravure (Roto): Direct rotary gravure with the cells engraved or etched in to the curved surface of a cylindric printing plate; or the cells may be formed in the outer surface of a wrap-around plate or tubular shell that is positioned over a cylindrical core. Offset Gravure Indirect gravure: An indirect printing technique that re-deposits ink from a gravure cylinder to a rubber coated cylinder which then applies the ink to the final substrate. |
| GRAVURE PAPER | Paper for gravure printing that has very low print roughness and good wettability of gravure inks. |
| GREASE RESISTANT PAPER | Any paper having good to very high resistance to penetration by grease or fats. |
| GREASEPROOF INK / COATING | Ink or coating that is resistant to the action of fats oils and greases. |
| GREY BALANCE | The values for yellow, magenta and cyan that produce a neutral Grey with no dominant hue when printed at a normal density. |
| GREYBOARD | A homogeneous board made usually of mixed waste papers with or without a screenings and mechanical pulp on a continuous board machine, in thickness less then 1mm. |
| GRIPPER SPACE | Clear space in the print for grippers. The number and positioning of spaces depend on the type of printing press, as gripping could be top, bottom, sides or all four sides. |
| GROUNDWOOD PRINTING PAPERS | A printing paper having groundwood or mechanical refiner pulp as part of it's fibre fibre furnish. The use of such mechanical pulp instead of all chemical wood pulps produces characteristics such as higher bulk, higher opacity for equivalent basis weight & greater softness. |
| GROUNDWOOD PULP | Stone ground wood pulp: The traditional mechanical wood pulp, mechanically prepared typically by grinding wood away from 4ft. Logs; used in the manufacture of newsprint, publication papers and Groundwood printing papers. Pressurized stone ground wood: A stronger pulp than "stone groundwood pulp” requiring less reinforcement with softwood chemical pulp, prepared in a pressure-sealed chamber. |
| GSM | Abbreviation for grams per meter square; units of grammage; metric unit alternative to Basis weight. |
| GUILLOTINE (Ream cutter, Trimmer) | International term for a machine equipped with a long heavy removable knife for trimming paper sheets with a downward slicing action. |
| GUM | A gum Arabic solution used to coat a lithographic plate at the end of its preparation, also before storage or during a stoppage on the press. The protective coating helps to prevent scumming. |
| GUMMING | The application of gum to paper as glue for various applications. |
| Definition | |
|---|---|
| HALFTONE | Halftone Print (Halftone image): A reproduction by Screening of continuous tone artwork, such as of a photograph, with the image formed by dots of various sizes and a constant degree of separation. Modifier applied to the process, plates and photographic film used to produce a halftone print. |
| HANDLING DAMAGE | Any physical damage to package or paper structure, which occurs during storage or movement of paper. |
| HARD EDGE (high edge, raised edge) | Localized extra hardness on a roll end, caused by a caliper band, usually with an adjacent thin caliper band. Detectable by observing the outer surface of the roll. |
| HARD-SIZED. | High water-resistance in paper from size added to make the paper resist moisture penetration. |
| HEAT TRANSFER PAPER | The paper used in Thermal transfer printing (Sublimation printing) |
| HEATSET (Heatset Printing) | Typically web printing in which the ink is dried by passing the printed web through a vented oven set at the temperature required to flash off ink solvents and produce a set image. |
| HEATSET OFFSET | Heatset printing where the inks have been printed by web offset lithography. |
| HIGH BULK BOOK PAPER | A book paper which has a bulking number of 440 to 344 pages per 25mm (1") for a weight of 67 g/m2. |
| HOLES | Holes of about pin-size in paper Wire holes: Clean edged holes without any contamination or foreign material. Pitch holes: Holes caused by pitch plugging the wire; sometimes pitch is evident at hole edges. |
| HUE | The quality of colour, which may be characterized by its position in the whole visible spectrum through blues, greens, yellows and reds. For the Additive Primary Colours, any three hues, conventionally a red, green and blue are selected such that any person with average colour vision can match any other hue by adding the three in varying proportions. For the Subtractive Primary Colours, which are the process printing colours, the three primary hues are Yellow, Cyan and Magenta, from which any other hue may be approximated. |
| HUMIDITY | A moderate degree of wetness, especially of the atmosphere. A papermaking term to describe the equilibrium relative humidity of the ambient air next to paper such as in the middle of a pile or roll of paper. |
| Definition | |
|---|---|
| IGT | Acronym for Institute Von Graphische Technologie. |
| IGT PRINT TESTER (IGT PICK TESTER) | A type of test instrument developed by IGT that among other things, measures, resistance of paper to pick or Delamination. |
| IMPRESSION CYLINDER | The backing cylinder of a web printing press supports the printing of a paper when the image is being pressed down on the paper from a printing plate or on offset blanket. |
| INDEX CARD | A rigid paper or board of appropriate quality and size used for recording data in library type of filing index systems. |
| INK COVERAGE | The degree of completeness of coverage of a printed surface with the intended ink film. the ration or percentage of ink film area covering a surface to the area covering a surface to the area intended to be covered. |
| INK HOLDOUT | The extent to which a printed surface resists penetration by the vehicle and pigment of a given ink formulation. |
| INK JET PRINTING | Printing process of an image or text by small ink particles onto the paper surface. |
| INK SETOFF | The transfer of ink from fresh prints to any other surface. First Impression setoff : set of that occurs when the paper is printed on the second printing nip while the print from the first impression is still fresh. |
| INK TACK | The body or cohesiveness of ink. The measure of tack as the force required to split an ink film. |
| INK WATER BALANCE | In Lithographic printing the optimal feed of ink and fountain solution to obtain target print density without adversely affecting the white areas. |
| INTAGLIO | Method of printings in which special ink is doctored into recessed cells that are engraved or etched into the printing plate, and the ink is transferred to paper while pressed into the plate surface in the printing nip. |
| INTERLEAVING | The insertion of sheets of one kind of paper between sheets of another kind of paper or material. |
| INTERNAL BONDING | The force with which fibres are bonded to each other within a sheet of paper. |
| INTERNAL SIZING | The process of adding various sizes internally to slurry of stock. The process of internal sizing with water-resistance sizes like rosin neutral sizes or alkaline sizes. |
| ISO | Acronym for the International Standards Organization |
| ISO 14000 | Set of worldwide environmental standards developed by ISO. |
| ISO 9000 | Set of worldwide quality standards developed by ISO. |
| ISO SIZE | Standard metric paper sizes recommended by ISO |
| Definition | |
|---|---|
| KNIFE COATING | A coating process in which a doctor blade, knife, or a straight edge is employed to spread and control the amount of coating on the paper, includes Air Knife coating, Blade coating. |
| KRAFT PAPER | Paper made substantially from any kind of sulphate (kraft) pulp. |
| Definition | |
|---|---|
| LABEL | A slip of paper or other material to be affixed to a container or article, and on which static data is pre-printed as a means of identification or to convey information (e.g. size, weight, price, barcode) |
| LAID LINES | A continuous watermark consisting of very close parallel lines, generally associated with spaced lines (chain lines) at right angles to these. |
| LASER PRINTING | Xerographic printing where a modulated laser ray is projected on to a photoconductive cylinder or belt by a rotating mirror. The laser serves to product the electrostatic latent image, which is developed with toners. |
| LEDGER PAPER | A grade of business paper generally used for keeping records. |
| LETTERHEAD | Printed heading on letter, stating name and other particulars of a person, company institution, authority, organization etc. |
| LETTERPRESS | Method of printing from a raised, relief surfaces by direct contact between the inked place and the paper surface. |
| LIGHTWEIGHT PAPER | Papers having a grammage (basis weight) normally less than 40 g/m2. |
| LINT | The material removed from paper due to linting. |
| LITHOGRAPHY (Litho / Lithographic Printi | Any process in which the printing is done from a plane (planographic) surface. Conventional Litho has the image photochemically reproduced onto the plate whose image areas carry ink and the non-image areas carry water and stay clean of ink. Offset(offset lithography): Lithography involving transferring the printing from plate to blanket to paper, the most popular printing process today. Dilitho: Lithography without using an offset blankets I.e. printing direct from plate to paper, the most popular printing process today. |
| LOT NUMBER | A number frequently used by manufactures and customers to identify a specific product or shipment; number for any group of rolls or packages in an order that is to be marked separately for the customer's convenience. |
| Definition | |
|---|---|
| MACHINE DIRECTION | That direction in a paper corresponding to the direction of the flow of the stock on the paper machine. Fibres tend to be oriented mainly in the machine direction. |
| MACHINE FINISHED | Paper treated mechanically on the paper making machine, with a device such as Calender stack, to improve the smoothness and uniformity of appearance on both side. |
| MACHINE GLAZED (MG) | The glossy finish produced on a Yankee machine. There the paper is pressed against a large steam-heated, highly polished revolving Yankee cylinder, which dries the sheet and imparts a highly glazed surface on the side next to the cylinder, usually leaving the other side rough. |
| MAGNETIC INK CHARACTER RECONGNITION (MIC | Fourteen stylized characters which must be imprinted to close tolerance-using ink with magnetic metal content. Used primarily in the banking industry for the encoding of checks and other documents used in that industry. |
| MATTE (Matt, Mat) | Dull finish of coated paper. The coating is a special formulation and there is little, if any, calendering. |
| MILL BOARD | A homogeneous board made usually of mixed waste papers with or without screenings and mechanical pulp on an intermittent board machine, in thickness not less than 0.5 mm. |
| MILL SPLICE (Splice) | A splice made at the paper mill. Usually the two ends of the web are joined in an overlap, with double-sided adhesive tape or with other adhesives. |
| MOISTURE CONTENT(Water content) | The percentage of water in a pulp, paper or paperboard. It is determined by completely drying the sample at 100-105*C. The result is expressed as a percentage of the original mass of the sample unless otherwise specified. |
| MOTTLED FINISH | A paper appearance, which is characterized by high and low spots or by glossy and dull spots. |
| MULLEN | This term for burst comes from the name of the Mullen tester, a popular instrument used in the test. |
| Definition | |
|---|---|
| OCR | Acronym for Optical character recognition |
| OFFSET | OFFSET Offset Printing (Indirect Printing): Printing method used especially in lithography; the ink is first transferred from the printing plate to a Blanket and then from the blanket to paper. However, the offset mode is also used commercially for printing letterpress (Dry offset) or gravure (Offset gravure) Offset paper: A grade of paper, such as offset book, designed to be printed by offset lithography, particularly to have higher surface strength to withstand the high ink tack forces from offset inks. |
| OFFSET GRAVURE | Indirect gravure printing using an offset blanket. |
| ON MACHINE | The operation of a process unit like a calender or coater as an integral part of the paper machine. |
| OPTICAL BRIGHTENER | Fluorescent dyes added to paper to enhance the visual brightness; the dye absorbs ultraviolet light and re-emits it in the visual spectrum. |
| OVEN DRY MOISTURE CONTENT (OD) | The percentage loss in weight of a paper specimen when dried to constant weight in an oven maintained at the temperature of 105=/-2C. |
| Definition | |
|---|---|
| PALLET | A low platform to hold a load of paper or prints, which is easily moved by a lift truck. It is fabricated of two separated layers of wood, paperboard or plastic. |
| PAPER | A name for a range of fibrous materials in the form of a coherent sheet or web used for writing, printing, wrapping, packaging, decorating, wiping etc. |
| PAPER FOIL | A paper laminated with metal foil. |
| PAPER MICROMETER | An instrument used for measuring the caliper of paper or paperboard. |
| PAPERBOARD/ CARD BOARD | Paper of heavier grammage than 180. |
| PARENT ROLL | A roll from the paper machine put into inventory, which is later slit into small rolls. |
| PENETRATION | Ink strike-through: The appearance of dark specks on the reverse side of a print due to ink penetration through the sheet, sometimes because of pinholes. The act or process of penetration of printing ink, writing ink or coating colour into paper. |
| PERFORATIONS | Intermittent cutting of slits along a line in paper or carbon. Intact paper bridges the space between the cuts. |
| PERMANENT PAPER | A paper that can resist large chemical and physical changes over and extended time (several hundred years) This paper is generally acid-free with alkaline reserve and a reasonably high initial strength. |
| PICK(picking) | The rupture of a fragment of paper from it's surface during papermaking or printing; leaving the fragment clinging or released; fragments may be flakes, fibres, fines or coating. Coating pick (Flaking): The removal or lifting of coating particles from the base sheet or from another coating layer during calendering or printing, so that voids or craters are visible at the coating failure. Wet pick: Resistance to picking of wet or dampened paper. Pick occurring when the paper surface is wetted by litho fountain solution and is subject to surface absorption of that aqueous solution and to associated weakening of the surface strength. Vessel segment pickout: Pickout of vessel segments, which are difficult to bond into the paper surface. large vessels occur in the ring porous hardwoods and break into rectilinear segments during cooking. |
| PIGMENTS | Substance that has been manufactured for ease of colloidal dispersion in inks coatings or papermaking stock to impart colour, opacity and / or control or rheological characteristics. |
| PINHOLES | Any small holes through paper or coating extending mainly through the stock; they are of pinpoint size, in Uncoated paper are visible when looking through the sheet. Pinholes caused by fine particles of sand, clay, slum etc, are crushed and fall out, leaving holes. |
| PIRA | Acronym for Printing Industry Research Association Leatherhead, and UK. |
| PITCH | Resinous material (usually dark) which originates from the wood and / or internal sizing resins. |
| PIV | Acronym for positive infinitely variable speed control as on sections of some paper machines and printing presses. |
| PLY | Each separate web, which makes up the sheet formed on a multi-layer machine. Each layer adds one web or ply, which is pressed to the other, the plies adhering firmly upon drying. |
| POROSITY OF BASE STOCK | The ability of base stock to pass air under controlled conditions as defined under Porosity. The control of base stock porosity is an important indicator to make the base stock suitable for the subsequent coating. |
| POST-CONSUMER FIBRE | Fibre derived from a finished product that has been collected after it passed through its life as a consumer item and would otherwise be discarded as solid waste. Examples are old newspapers, office waste, and computer printouts, tabulating cards, milk cartons and rags. |
| POSTCARD | A card on which a message may be sent without an envelope. They may be pre-stamped. |
| PRINT QUALITY | The degree to which a print's appearance and other properties approach the standard or the desired result. |
| PRINT TESTER | Devices made to simulate press-printing variables for the assessment of papers and inks under controlled conditions. Those in common use are IGT print tester, Proof press, Prufbau print tester, RNA print tester, Vandercook proof press. |
| PRINTABILITY | The ability of paper to give the most faithful reproduction of the original image at the maximum efficiency. |
| PRINTING INK | PRINTING INK An ink containing pigments and / or dyes to produce print images. Printing inks are: EB-curing ink: Ink made for in line curing by electron beam radiation for high gloss and high scuff resistance, using highly reactive cross-linking vehicles which cure and dry under electron beam radiation. Flexographic Ink: Liquid ink of either water or organic solvent base for flexographic printing. Gravure Ink: Liquid ink, usually solvent based, sometimes waterbased, for gravure printing. Heatset Ink: Ink used in Heatset printing, using hydrocarbon solvents, hard soluble resins, drying varnishes and plastisizers. Letterpress ink: An oil ink used for sheet fed letterpress or webfed. News ink: Letterpress oil ink of high fluidity; using low cost mineral oil and carbon black. Quick set Ink: Ink, which sets quickly. Useful for coated paper and board. Thermal curing Ink: Ink, made for thermal in line curing; using reactive crosslinking vehicles, little or no solvent. UV curing Ink: Ink made for inline curing by ultra violet radiation, for high gloss and high scuff resistance. Water base ink: Ink whose ink components have been dispersed or dissolved in water. |
| PRINTING PAPER | Any paper suitable for printing, such as w/p paper, newsprint & coated paper. PROFILE (Web Profile) The varying values of a property of paper or print with respect to a specified distance in a specified direction. CMD profile: Profile in the cross-machine direction. MD profile: Profile in the machine direction. Diagonal profile: Profile in the diagonal direction. |
| PRUFBAU PRINT TESTER | A Print tester, first developed by Prufbau that simulates multicolour printing. |
| PUNCHED PAPER TAPE | Traditionally used in automatic date processing to perpetuate the typewritten or punched card date without recopying. |
| Definition | |
|---|---|
| QUALITY CONTROL | The process of testing representative samples to check the consistency or quality. |
| Definition | |
|---|---|
| RAG CONTENT | The proportion of natural fibre rag like cotton in a paper furnish. |
| RATTLE (Snap) | That combination of properties such as stiffness density etc. which is responsible for noise when the sheet is shaken or flexed. |
| REAM | A number of sheets of paper, commonly either 480 or 500 according to grade. |
| REAM SIZE | Area of paper in a ream, as indicated by (inches width) x (inches length) x (number of sheets / ream). |
| RECYCLABLE PAPER | Paper that can be easily recovered to make new paper. |
| REFLECTANCE | The amount of light reflected by a paper. |
| RELATIVE HUMIDITY (RH) | The ratio of the amount of moisture in the air at any temperature to the amount required at that temperature to saturate the air, expressed in percentage. |
| RETENTION | The amount of filler material or other material which remain in the finished paper expressed as a percentage that added to the furnish before sheet formation. |
| RIDGES | Roll defect where there are raised bands or rings of material around the circumference of the roll. |
| ROLL COATING | A process in which the coating is applied by roll and subsequently smoothed by means of reverse rolls contacting the freshly coated surface. |
| ROUGHNESS | The characteristics of high and low physical areas of paper deviating from the plane of its surface, the roughness being of visual to microscopic proportion. |
| RUB-OFF (INK RUB OFF) | The degree to which ink can be removed from the printed surface by rubbing. |
| Definition | |
|---|---|
| S C | Acronym for Supercalendered finish. |
| SAMPLING. | Technique for obtaining representative samples of paper or pulp. |
| SATIN FINISH | A smooth, satin-like, semi-glossy finish of paper or Bristol. |
| SCOTT BOND STRENGTH | A kind of Z-direction tensile strength that results from a fast impact rather than the slower tensile tester method. |
| SCREENING | The process of creating a Halftone print, I.e. a print with areas of lower optical density than of the ink film, by the use of a fine pattern of ink dots. |
| SCUFF RESISTANCE | The resistance to scuffing of paper or paperboard, usually measured in terms of the number of cycles required to produce a specified degree of scuffing on a specified area with a designed abrasive object of specified size and weight rotating or reciprocating at specified speeds. |
| SCUMMING | The printing of an unwanted light tint in the Non-image areas of print, due to a faulty plate. |
| SECURITY PAPER | Paper which incorporates identification features to deter counterfeiting and forging. |
| SEMICHEMICAL PULP | A pulp produced from the raw material by middling chemical treatment between that of chemical pulping and chemi mechanical pulping, followed by a mechanical defibration operation |
| SHADE | In ink and paper, a synonym for Hue. |
| SHEET | A rectangular piece of paper or board. |
| SHEETER. | In printing, a knife, usually rotary, at the delivery end of a press or collator that cuts off web press lengths into individual sheets, usually followed by a stacking or piling device. |
| SHIVE | A bundle of incompletely separated wood fibres, which may appear in the finished sheet as an imperfection. Commonly found in papers from mechanical pulps. |
| SIDE RUN | A roll differing in width from that of the rest of the rolls being made at the time on the slitter. |
| SIZING PROCESS | The addition of materials to a papermaking furnish or the application of materials to the surface of paper and board to provide special qualities to the paper. |
| SLIME HOLE | A hole in paper, characterized by brownish translucent material around the edges. Caused by a lump of slime which has formed in stock system from the growth of micro organisms, then becoming detached and flowing onto the paper machine wire with the fibre to form a non-fibrous area. |
| SLITTER | A machine direction web cutting device which is mounted on a rewinder for transforming large parent rolls into rolls having narrower widths. Shear Cut Slitter: Slitting done by circular flat faced female Knives in slight edge contact with and positioned directly below interacting male knives, the paper running between the two. Score cut slitter: Slitting done by circular Knives having V-shaped cutting edges, driven by contact with a platten roll or drum around which the paper web travels. Razor blade slitter: A slitter using a blade to cut a taut web; mainly for film and paper. |
| SMUDGE. | A blurry spot or streak of printing ink on a print, caused by ink on that or another print when the ink has not yet fully dried. |
| SODA PULPING | An alkaline pulping process that uses a simple, sulphur-free cooking liquor of sodium hydroxide. |
| SOFT SPOT | Spot along the length of a roll that is flabby compared to the adjacent parts of the roll. |
| SPECK | A small defect of foreign substance with contrasting appearance to the surrounding paper. |
| STARCH | Starch is generally converted from the raw starch thermally, chemically or by enzymes to have better retention in the paper stock as it is being formed. |
| STATIC ELECTRICITY | The electrical charge which sometimes collect on paper owing to contact with dryer drums, Calender stack and in printing. |
| STENCIL-DUPLICATING PAPER | An oil-absorbent paper with a toothy surface. |
| STIFFNESS | That property of paper by which it resists deflection from an external source. |
| STRAW PULP | Pulp that is made from the straw of grains such as rice straw. It is cooked by soda process. |
| STRAWBOARD | Board made from partially cooked straw, bagasse or grass or a mixture of these. |
| STRETCH | Elongation of paper under tension. The elongation is expressed as a percentage of the original length when stressed at a stated load. |
| SUBSTRATE | Material such as paper or plastic, generally in sheet or web form. |
| SULPHATE PROCESS | Alkaline process of cooking pulp. |
| SULPHITE PROCESS | Acid process of cooking pulp. |
| SUPERCALENDERED FINISH | Finish obtained by passing paper between the rolls of a Supercalender under pressure. The Supercalender consists of alternate chilled cast iron and paper/cotton rolls. |
| SURFACE STRENGTH TEST | The method consists of printing a strip of paper in a print tester at an accelerating rate. The method is preferable to Wax Pick. |
| Definition | |
|---|---|
| TAPPI | Acronym for the Technical Association of the Pulp and Paper Industry, Atlanta, GA, USA. |
| TEARING RESISTANCE | The force required to tear a specimen under standardized conditions. |
| TELESCOPED ROLL | A defective paper roll with one end concave, the other convex instead of square; usually caused by slippage of the inner layers of the web. |
| TENSILE STRENGTH | The force, parallel with the plane of the paper, required to produce failure in a specimen of specified conditions of loading; expressed as load per unit with, e.g. kilo-Newton per meter (kN/m) or pounds force per inch. |
| THERMAL PAPER | Any paper with a heat-sensitive coating on which an image can be produced by the application of heat. |
| THERMAL TRANSFER PRINTING (Sublimation p | Printing whereby a design image is first printed on heat transfer paper using inks with sublimable dispersed dyes. |
| THERMOMECHANICAL PULP (TMP) | Mechanical pulp made by steaming wood chips under pressure prior to and during refining, producing a higher yield and stronger pulp than regular refiner wood pulp. |
| THICKNESS | See caliper. |
| TISSUE PAPER | Thin, soft paper made from strong cellulose fibrous materials and of a substance usually between 12 and 25 gsm. |
| TMP | Acronym for thermo-mechanical pulp. |
| TONE | The visual density of a printed area. Tone is the combined effect of the percentage of the image area covered with ink and the colour density of the ink in this area. |
| TONER | In ink making, organic dyes precipitated in an insoluble form as a pigment. In copiers, a powder or liquid of pigmented particles, used in electrostate processes like xerography, to form the copy's image of the original. |
| TRANSLUCENT DRAWING PAPER | A paper suitable for drawing office use; sufficiently translucent for an image on it to be reproduced by processes using transmitted light and for a design to be traced on it from an original placed beneath it. Such processes include blueprint and diazo. |
| TRIM | To cut true to exact size, by cutting away the edges of paper in the web or sheet. |
| TWIN-WIRE MACHINE | A paper machine, distinct form a single wire " Fourdrinier " machine, has two wires which sandwich the pulp slurry and permit faster drainage since drainage is from both sides; it can produce paper with less two-sidedness at higher speeds. |
| TWO SIDEDNESS | The difference in shade, finish or texture between the two sides of paper or paperboard. |
| Definition | |
|---|---|
| UNSIZED | Descriptor for paper to which no sizing has been added. |
| Definition | |
|---|---|
| VARNISH (OPV) | A thin, protective coating applied to a printed sheet for protection and appearance, providing a dull or high gloss product. |
| VEGETABLE PARCHMENT | Paper that has acquired, by the action of sulphuric acid, a continuous texture. It offers high resistance to disintegration by water and grease. |
| VELLUM FINISH | A toothy finish, which is relatively absorbent for fast ink penetration. |
| VISCOSITY | Resistance of a fluid to flow. In printing inks, a broad term encompassing the properties of tack and flow. |
| Definition | |
|---|---|
| WATER RESISTANCE | The resistance of paper to water absorption into paper. It is typically provided by Internal Sizing with rosin. |
| WATER VAPOUR PERMEABILITY | Rate at which water vapour passes through a sheet. |
| WATERMARK | Localised modification of the formation and opacity of a sheet of paper while it is still quite wet, so that a pattern, design, or word group can be seen in the dried sheet when held upto the light. |
| WAX PICK | A pick resistance test using wax. It uses a series of hard resins, non oily waxes which are graded in adhesive powers and which are pulled from the surface of the test paper, the highest numbered wax in the series which does not disturb the surface of the paper is the numerical rating of pick resistance. |
| WEB | Continuous sheet of paper coming from a paper machine; a thin layer of paper unwinding from a roll and threading through a rewinder, a printing press to other converting operation. |
| WET RUB RESISTANCE (WET RUB) | Resistance of a print to rub-off when the print's ink has not yet dried. |
| WIRE MARK | The impression left in the paper by the forming wire or dandy roll wire of the paper machine. |
| WIRE SIDE | That side of the sheet of paper which was formed in contact with the wire of a Fourdrinier paper machine during the process of manufacture. |
| WOVE PAPER | Paper having a uniform unlined surface and a soft smooth finish. |
| WRAPPER | The materials, consisting usually of paper or paperboard, sometimes with treatment for moisture barrier properties, which are used to protect the roll or pile form damage. |
| WRAPPER WASTE | The loss in weight of a roll represented by the weight of the wrapper. |
| WRINKLE / BLADE WRINKLE | Blade coating defect, an irregular line on the coated surface, essentially in the machine direction. |
| | Definition |
|---|---|
| XEIKON | A web-fed Electrophotographic printer using dry toner that prints two-sided four-colour copies. |
| Definition | |
|---|---|
| YELLOWING (REVERSION) | A yellowing deterioration of the brightness of pulp and paper by the action of air, light or heat. Papers made with Mechanical pulp such as newsprint and with other lignin-containing pulps are particularly susceptible to light reversion. |
| YELLOWNESS | Attribute by which an object's colour is judged to depart from preferred white toward yellow. |