glossary

Absorption
In paper, the property that causes it to take up liquids or vapors in contact with it. In optics, the partial suppression of light through a transparent or translucent material.

Against the Grain
Folding or feeding paper at right angles to the grain direction of the paper.

Artwork
Text, graphic and illustrations arranged individually or in any combination for subsequent printing.

Bindery
Place where final trimming, stitching/stapling, order-form insertion, and any necessary off-press folding is done.

Black-and-White
Originals or reproductions in single Colour, as distinguished from multiColour.

Blanket
In offset printing, a rubber-surfaced fabric that is clamped around a cylinder, to which the image is transferred from the plate and from which it is transferred to the paper.

Bleed
Printed matter which runs off the edge of the page. (usually 3mm)

Blocking
In binding, to impress or stamp a design upon the cover. The design can be blocked in coloured inks, gold leaf or metal foil.

Bond Paper
A grade of writing or printing paper where strength, durability and permanence are essential requirements; used for letterheads, business forms, etc.

Brightness
In photography, light reflected by the copy. In paper, the reflectance or brilliance of the paper.

Bulk
Thickness of paper.

Caliper
The thickness of paper, usually expressed in thousandths of an inch (mills).

Camera-ready
Artwork or copy which is ready for photography.

CD-ROM (Compact Disc Read Only Memory)
In digital pre-press, a laser enclosed optical storage disc that can store 650 Megabytes to over 1 Gigabyte of data on a disc about the size of a traditional 5-inch floppy disk.

Chromalins
One method of proofing a colour separation. Four separate, extremely thin plastic sheets (one of each Colour) are overlaid, producing a colour reproduction of the film separations.

Colour Separation
The process of separating colour originals into the primary printing colour components.

Continuous Tone
A photographic image that contains gradient tones from black to white.

Contrast
The tonal gradation between the highlights, middle tones, and shadows in an original or reproduction.

Cross direction
In paper the direction across the grain. Paper is weaker and more sensitive to changes in relative humidity in the cross direction than the grain direction.

CTP
'Computer to plate' The process of producing printer's plates directly from the computer with no films involved.

Curl
In paper, the distortion of a sheet due to differences in structure or coatings from one side to the other, or to absorption of moisture on an offset press.

Cyan
Hue of a subtractive primary and a 4-Colour process ink. It reflects or transmits blue and green light and absorbs red light.

Cylinder Gap
In printing presses, the gap or space of a press where the mechanism for plate (or blanket), clamps and grippers (sheeted) is housed.

Densitometer
In photography, a photoelectric instrument which measures the density of photographic images, or of Colours. In printing, a reflection desitometer is used to measure and control the density of colour inks on the substrate.

Density
The degree of darkness (light absorption or opacity) of a photographic image.

Die-cutting
Stamping out print with a custom made cutter to produce a folder or another individual shape.

Dot Gain
The enlargement of halftone dots on the press resulting in a loss of detail in the image.

Dots Per Inch (dpi)
A linear unit of measurement used to give the resolution of non-impact page printers. Dots per inch is the equivalent to 'spots per inch' (spi).

Dummy
A sample of a proposed job made up with the actual material and cut to the correct size to show bulk, style of binding etc.

Duotones
An image printed in two colours rather than one (greyscale). Normally, black is used together with a further colour. Duotone is used as an alternative to standard greyscale images, as the technique offers a softer, more detailed result.

Embossing
Pressing a pattern into a paper using a raised or etched relief.

Final Proof
The last proof before sending material to the printer, showing all corrections.

Finishing
This covers all operations after printing; also the hand operations of lettering and ornamenting the covers of a book.

Flush (left or right)
Flush left means the left ends of lines of type line up vertically; flush right means to line up the right ends of type.

Form Rollers
The rollers, either inking or dampening, which directly contact the plate on a printing press.

Fountain Solution
In lithography, a solution of water, a natural or synthetic gum and other chemicals used to dampen the plate and keep non-printing areas from accepting ink.

Four colour Process Printing
Colour printing by means of the three subtractive primary colours (cyan, magenta, yellow) and black superimposed; the colours of the original having been separated by a photographic or electronic process.

Four-up, Three-up, Two-up
Number of similar items printed on one sheet of paper. Also called four-to-view, three-to-view, etc.

Ghosting
Occurs when a ghost image appears in the printed image. It results from inadequacies of the inking system, i.e. uneven ink take-off from the rollers. Ghosting always appears on the same side of the sheet that the printing takes place.

Grain of the Paper
Machine made paper is made up of many fibers, which in general, tend to line up in one direction due to the nature of the process. This produces a preferred direction or grain, along which it is easier to fold, bend, or tear the paper. Cut sheet laser printers generally use long grain paper in which the grain runs parallel to the long side of the paper.

Grayscale
The depiction of grey tones between black and white. A greyscale monitor is able to display grey pixels as well as black and white, but not colour pixels.

Gutter
The binding margin of a book or the spine of a folder which allows for paper to be stored inside.

Halftone
The reproduction of continuous-tone-images, through a screening process, which converts the image into dots of various sizes and equal spacing between centers or dots of equal size with variable spacing between them.

Imposition
The order in which the pages of a printed product are placed so that they appear in the right order after folding.

Impression Cylinder
In printing, the cylinder on a printing press against which the paper picks up the impression from the inked plate in direct printing, or the blanket in offset printing.

Laid Paper
Paper with a pattern of parallel lines at equal distances, giving a ribbed effect.

Laminating
The application of transparent plastic film, usually with a high-gloss finish, to the surface of printed matter to enhance its appearance and to increase it durability.

Landscape
Oblong paper, having its long sides at head and foot.

Layout
The drawing or sketch of a proposed printed piece. In platemaking, a sheet indicating the settings for a step-and-repeat machine.

Lithographic printing
A process in which the printing and non-printing surface are on the same plane and the substrate makes contact with the whole surface. The printing part of the surface is treated to receive and transmit ink to the paper, usually via a blanket, the non-printing surface is treated to attract water and thus rejects inks from the ink roller, which touches the whole surface.

Make-Ready
In printing, all work done to set up a press for printing.

Middle Tones
The tonal range between highlights and shadows of a photograph or reproduction.

Moiré
In colour process printing, the undesirable screen pattern caused by incorrect screen angles of overprinting halftones.

Negative
In photography, film containing an image in which the values of the original are reversed so that the dark areas in the subject appear light on the film and vice versa.

Opacity
The property of the paper that blocks the transmission of light and the amount of ink showing through the sheet.

Pantone Matching System (PMS)
A colour guide to help visualize, communicate and control applied process Colours for type, logos, borders, backgrounds and other graphics treatments.

PDF
Program development facility or portable document format [Adobe].

Perfect Binding, glue setting
A threadless form of binding, whereby the printed product is bound using dispersion adhesive or thermoplastic.

Perfecting Press
A printing press that prints both sides of the paper in one pass through the press.

Perforation
Running a dotted score into paper to allow the paper to be pulled apart.

Picking
In printing, the lifting of the paper surface during printing. It occurs when pulling force (tack) of ink is greater than surface strength of paper.

Pixel
Short for "picture element". A pixel is the smallest resolvable point of a raster image. It is the basic unit of digital imaging.

Plate
A metal or paper light-sensitive sheet. It holds the image to be printed. The image gets on the plate by a photographic process. During printing, the image on the plate picks up ink, which is then indirectly transferred to paper.

Plate Cylinder
The cylinder of a press on which the plate is mounted.

PMS
see Pantone Matching System

Point
Typographic unit of measurement equal to 1/12 pica or 1/72 inch. The point size of a font is measured from the bottom of the descenders to the top of the ascenders. Points are always used to express type size and leading.

Portrait
Oblong paper, having its short sides at head and foot.

Positive
In photography, film containing an image in which the dark and light values are the same as the original. The reverse of negative.

Preflight
In digital prepress, the test used to evaluate or analyze every component needed to produce a printing job. Preflight confirms the type of disk being submitted, the colour gamut, colour breaks, and any art required (illustrations, transparencies, reflective photos, etc.) plus layout files, screen fonts, printer fonts, EPS or TIFF files, laser proofs, page sizes, print driver, crop marks, etc.

Prepress
Those steps needed to transform the finished original copy into the printing plates or other forms needed for reproduction.

Preprinted Form
A cutsheet, fanfolded or continuous-roll form that has been offset printed with constant copy or design onto which variable data can be imaged.

Process Colours
Black and three primary Colours-magenta (red), cyan (blue), and yellow- into which full-Colour artwork is separated before printing.

Proof
Working copy used for review and approval.

Ream
Five hundred sheets of paper.

Register
In printing, fitting of two or more printing images in exact alignment with each other.

Resolution
In electronic imaging, the qualification of printout quality using the number of dots per inch.

Score or Crease
To partially cut/crease with a rule into heavy paper or board to break the grain and so enable easier folding.

Screen Angles
In colour reproduction, angles at which the halftone screens are placed with relation to one another, to avoid undesirable moiré patterns. A set of angles often used is: black 45 degrees, magenta 75 degrees, yellow 90 degrees, cyan 105 degrees.

Screen printing
Often called silk screen printing from the material formerly used for the screen. A stencil process with the printing and non-printing areas on one surface. The printing (image) area is open and produced by various forms of stencil. the substrate is placed under the screen and ink is passed across the top of the screen and forced through the open (printing) areas on to the substrate below.

Separations
Colour separations either prepared by an artist using separate overlays or computer generated artwork for each colour or achieved photographically by use of filters.

Sheet Fed
Relating to a printing technique whereby paper is fed into the printing press in single sheets, as opposed to paper on a roll.

Spot colour
Any area of colour that is not printed using a CMYK process set; coloured areas reproduced using self-coloured inks, such as Pantone inks.

Stock
Paper or other material to be printed.

Tack
In printing inks, the property of cohesion between particles- the separation force of ink needed for proper transfer and trapping on multiColour presses. A tacky ink has high separation forces and can cause surface picking or splitting of weak papers.

Tints
Various even tone areas (strengths) of a solid Colour.

Trapping
In printing, the ability to print a wet ink film over previously printed ink. Dry trapping is printing wet ink over dry ink. Wet trapping is printing wet ink over previously wet ink. In prepress, refers to how much overprinting Colours overlap to eliminate white lines between Colours and printing.

Typeface
A printing type of a specific design.

Typesetting
Assembly of reading matter by the use of handpicked metal type, and/or by casting or phototypesetting, more usually these days by keyboarding!

UV inks
In printing, solventless inks that are cured by UV radiation. They are used extensively in screen printing, narrow web letterpress and flexographic printing.

Varnish
To apply oil, synthetic, spirit, cellulose or water varnish to printed matter by hand or machine to enhance its appearance or to increase its durability.