In our business, it is a necessity to know basic paper and printing terms. Use the glossary for a quick reference or browse it to refresh your knowledge.
Select from the general listing below:
C1S
Paper that has been "coated one side"; label paper.
C2S
Paper that has been "coated two sides"; coated paper for text, publication, or commercial printing.
calcium carbonate
A white pigment used in the furnish or coating of paper. In the furnish, limited to alkaline or neutral internal sizing systems. The calcium carbonate can be obtained from grinding naturally occurring limestone (ground calcium carbonate or GCC) or manufactured as a precipitated pigment (precipitated calcium carbonate or PCC).
calender crush/blackening
A term describing the darkening of the intended shade of paper caused by excessive calendering or by the calendering of wet paper.
calender cut
A cut in the web of paper, usually at an angle to the machine direction, as a result of wrinkles or excess paper accumulating as a fold at the entrance of a calender nip. When the excess suddenly carries through the nip, the force applied in the nip cuts the sheet.
calender marks
Marks imparted by the calender, at a repetitive interval depending on the diameter of the damaged calender roll causing the defect. The defect usually appears as a dull, irregularly shaped area when viewed by low angle light.
calender scale
See scale.
calender spots
Marks or spots of a non-uniform size and shape, on or impressed into the surface of paper, caused by foreign material sticking to a calender roll. The defect will repeat, depending upon the diameter of the roll causing the defect; the defect usually appears as a transparentized spot when viewed through the sheet.
calender stack
See calendering.
calender streaks
Are relatively high(er) gloss bands in the machine direction, resulting from non-uniform wet pressing, drying, coating, etc, and these bands gloss more in the calender.
calendering
The equipment (calendar) and process which smoothes and densifies (controls thickness or caliper) a web of paper; rotating rolls under pressure, with the web running between the two; on the paper machine, called the machine calender, with the rolls being of a steel or metal composition; also see supercalendering. Collectively, the calender rolls in the equipment to do the calendering are called the calender "stack".
caliper
The thickness of a sheet of paper measured under specified conditions, generally expressed as one-thousands of an inch (0.001"), 11 mils or points; measured with instrument called a micrometer or caliper.
camera-ready copy
As the name implies, this is copy to be printed which is ready to be photographed without further alteration.
can
One of the drying cylinders in a paper machine dryer section.
caption
Text describing an illustration, placed adjacent to it.
case bound
Also hardbound; a book with a stiff cover, which is made separately, with the sewed book being inserted and fastened (called casing); the stiff cover is called the case.
casing-in
See case bound.
cast coating
The coating method in which a wet coating on the surface of a web is cast against a highly polished, rotating, Chromium plated dryer drum; a mirror, high gloss finish results.
cellulose fibers
The primary ingredient or raw material in making paper; derived primarily from plant sources, mainly wood, but can be obtained from cotton, sugar cane, or other plant sources; The fibrous material remaining after the nonfibrous components of the wood (or other plant) have been removed by the pulping and bleaching operations.
chalking
A condition in a printed image (or coating) in which the pigment is not properly bound to the paper and can easily be rubbed off as a powder (or flushed off with water); usually an indication of improper ink or coating drying, excessive absorbency of the paper, or insufficient binder.
character of fold
See fold quality.
chemical ghosting
See ghosting.
chemical pulp
See pulping.
chest
A storage tank in the paper industry used especially for stock, pulp, furnish, water, white water, etc.
chill rolls
Rolls located immediately after heated or drying ovens on either paper making, coating, or printing equipment, to lower the temperature of the web, and in the case of heat-set inks, to the "setting" temperature of the inks. Can also be called cooling rolls or sweat rolls.
chopper fold(er)
clay
A pigment (kaolin type material) used as a filler (for opacity or smoothness) in the making of paper, or in the paper coating.
clothing/machine clothing
Paper machine term for the wire, wet felt or dryer felt.
coated paper
Paper that has been coated with a material to provide printing ink holdout, smoothness, and levelness.
coating lump
Also, color lump; a lump of dried coating, most commonly from 1/16 to 1/4 inch in diameter, which has been redeposited on the web of paper, usually from some place on the coating equipment; can even be a splash of coating (coating splash) on the sheet during or after the original coating application.
coating scale
See scale.
coating splash
See coating lump.
coating streak
A band of lighter or heavier than normal coating material, wider than about 1/8". Steaks are in the machine direction, and appear as more or less transparent than the surrounding area when viewed by transmitted light. Streaks are generally caused by a disturbance to the coating during or after application to the paper web. A "drag mark" is actually a coating streak, created by a foreign material dragging against the coated surface (wet or dry) and creating a disturbance in the coating.
cockle or cockling
A surface that is "puckered" or with a rippling effect, intentionally obtained by air drying under minimum tension; simulates hand made, air dried paper; as a cockle finish, is a desirable effect. As an unwanted, localized surface roughness or puckering, cockle is considered a defect.
collating
The interleaving or collecting of flat sheets, signatures, or webs (business forms) in the proper sequence before binding, crimping/fastening/gluing, or edge padding; also called "gathering" when dealing with signatures.
color
Coating mixture, either white or colored.
color down
Refers to the sequence of applying printing inks to the paper, i.e., the magenta could be the 2nd "color down" in a "four-color process" job.
color lump
A hard lump of coating on the surface of a sheet of coated paper. See also <i>coating lump</i>.
color measurement
1) Of papers: An instrumentation reading of color. One such system is by MacBeth, and uses the "color coordinates" of "L,a,b", where "L" signifies a lightness value from black to white, the "a" value ranges from red to green, and the "b" value from yellow to blue. 2) Of printing inks: Several color matching "libraries" exist (of from 700 to over 3000 colors each) for printing ink color matching, including the industry standard for spot colors, Pantone. See also <i>PMS color</i>.
color scanner
A system and equipment that allows a computer to simulate photographic techniques to accomplish screening for tonal value and color separation, electronically.
color separation
The process of separating full color originals into the primary printing colors; see "three-color and four-color process"; can be accomplished either photographically or electronically.
color sequence
The order or sequence in which various colors of inks are printed; also laydown sequence. In multi-color printing, the trapping of each color down depends upon the lower tack of each successive color, i.e., jelly applied to peanut butter, not peanut butter applied to jelly.
colors
See primary colors.
commercial register
Historically, color printing on which misregister allowable is one row of dots. Can also imply any subjectively acceptable registration and is dependent upon the job being run. See also <i>register</i> or <i>hairline register</i>.
conditioning
Laboratory (see TAPPI), paper finishing, or pressroom ambient temperature and relative humidity conditions: paper manufacturers and printers need to provide the same conditioning for the paper, for optimum paper stability and performance, under equilibrium conditions. Also refers to the act of bringing paper over time to the pressroom condition.
coniferous
Cone bearing trees that do not shed their leaves seasonally, like pine and fir; also known as "softwood". Pulps made from this type of tree give cellulose paper making fibers that are long, thus "long fiber" pulp.
contact angle
The angle at which a drop of fluid (like fountain solution or ink) makes with a surface (such as paper) after a specified period of time; usually a measure of the surface or internal sizing, or a measure of the absorption characteristic of the surface being tested for the fluid applied. A low contact angle indicates good or high absorption, while a high contact angle (for example, a 90-degree angle of the edge of the droplet with the plane of the paper) indicates resistance to surface wettability or lack of absorption of the fluid by the surface.
continuous forms
Business forms produced in a continuous or web format, which may be cut (see unit set forms) to individual length or perforated for easy tear to individual length, at the forms manufacturer, or during or after use. May also be used in the continuous format, in roll or fanfold/accordion form; frequently used on automatic, pin feed units.
continuous tone
A continuous and smooth transition of tones from one tonal value to another, as obtained in photographic prints. See also <i>tonal value</i>.
conversion coated
Paper which is coated on one or two sides, after it is off the paper making machine. See also <i>machine coated</i>.
cooling rolls
See chill rolls.
copy
The furnished material (typewritten or line work, pictures, artwork, etc.) to be used in the production of the printed job.
copy(ier)/duplicator
When used in either form as a single term, refers to a system and equipment which relies upon electrostatic reproduction principles to either generate an offset lithographic plate, or even the copies themselves, directly from the electrostatic photoreceptor.
copying
The act of producing an image on paper which is a duplication of the image of another document, such as by a photographic or xerographic process, or with carbon or carbonless papers.
Corona
A device used to place a uniform electrical charge on the surface of an electrostatic/xerographic photoreceptor.
corrugating
See fluting.
corrugation
See rope.
cotton fiber paper
Paper made using 20% or more cellulose fiber derived from sources of cotton, i.e., garment clippings, cotton linters (short fibers that adhere to cotton seeds) or waste, and originally "rags" - therefore rag content paper.
couch marks
See shadow marks.
cover paper
A general term applied to heavier basis weight durable printing papers, normally used for outside covers, such as on pamphlets and magazines; measured on a 20" x 26" basic size.
cracked edge
A slight tear in the edge of a web, which under tension can initiate a web break.
creep
In offset lithography, the forward movement (or stretch) of a printing blanket during printing. This can result in doubling. Can also apply to the movement of the packing under the plate or blanket during printing, causing excessive plate wear.
cross direction
See grain direction.
crossline screen
Originally in halftone or tonal photography, a grid pattern with opaque lines crossing each other at right angles, creating transparent squares or apertures through which the dots were produced to form an image giving the illusion of printed tonal values. See also <i>screen</i>.
crown
See roll crown.
crushed core
Core out of round or completely collapsed as a result of excessive squeeze or impact.
curl
See simple curl.
cut-line
A caption placed inside the illustration.
cut-off
In any web printing, the cut length of paper prior to the delivery. The maximum cut-off length is the circumference of the plate cylinder or plate length.
cut-outs
Printed pieces cut into irregular shapes, or with cut out holes (like an envelope window).
cut-size paper
Refers to any lift of paper, which is 17" x 22", or less in dimensions. Generally, specific to business papers which are generally cut-to-size" to 8 1/2" x 11", 8 1/2" x 14" (legal size), 11" x 17", or A4A size.
cyan
See process colors.
cylinder gap
On a printing press, the gap or space across the plate or blanket cylinder around its circumference, housing the clamping mechanisms for holding the plate or blanket in place; can be called blanket gap or plate gap.
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