Acetate —A high-quality, transparent sheet of plastic commonly used as a layer in multi-layer artwork or composition. Acetate is also used for overhead transparency printing.

Aliasing—The pixelated or stair-step appearance of slanted or curved lines on low-resolution, computer generated images. Also called jaggies. Ragged edges on computer-generated elements are less visible when output on a high resolution output device.

alkaline paper—A stable, acid-free paper used for products that must resist deterioration and preserve their images for as long as possible. Archival photographs, high-quality books, and fine art prints are made on alkaline paper.

American National Standards Institute (ANSI)—Pronounced an-see.ANSI is a nonprofit organization that provides administrative support to standards development activities within the United States. It is the sole U.S. member body to the International Organization for Standardization (ISO) and is the organization through which all official U.S. input to ISO takes place. It has four basic functions, (i) facilitate U.S. standardization policy developments, (2) accredit national standards developers, (3) promote U.S. standards interests globally and (4) provide information and training on standardization. apparent dot area (ADA)—The dot area of a printed halftone. author's alterations (AAs)—Corrections made in proofs (galley proofs, bluelines, color proofs) that are not caused bv printer error.

binder—An adhesive component of-paper designed to hold the paper togther

binding—Binding begins after a printer has faid the ink on the paper. It includes cutting, folding, trimming,gathering (collating), stitching, pasfing, insetting, casing-in, etc.

bit—Abbreviation for binary digit. The smallest unit of information in a binary system, a bit is the fundamental unit of information used in computers. A bit element is a I signaling on or a o signaling off in a data string. Most computers work with 8-bit strings called bytes.

bitmap—A computerized image made up of (jots or pixels. While satisfactory for pixel-based screen displays. bitmap images give a jagged appearance on paper or film. For high-quality print output, bitmap images must be translated to raster images.

black plate change—Changes made to black text and headlines in process printing. The changes are made on the black plate and thus do not affect the color.

blanket—A fabric-reinforced sheet of rubber used on offset presses to transfer the impression from the plate onto the paper.

bleed—Printed colors that run all the way to the edge of a page. To accommodate the bleed, the printer must make the bleed area larger than the final trim size. The page is then trimmed right through the bleed area. Thus, bleeds requires more paper and printers charge extra for them.

blind folio—Page numbers are not printed on the page.

blueline—A photographic proof for checking the accuracy of layout and position before printing plates are made.

brightness—Also called value, (i) One of the three attributes of color, the other two being hue and saturation.Brightness describes differences in the amount of light reflected from or transrmitted through an image regardless of its hue and saturation. This is a difficult word to use in marking color correction. People use it for both the addition and subtraction of color. Correctly used. it refers to the amount of light (paper white) apparent in an area, (2) When speaking about paper, brightens is the light reflectance or brilliance of the paper at a specific wavelength, often perceived as whiteness. Generally, the higher the brightness

CiS— A trade acronym for coated I (one) side. Commonly card stock used for postcards and fliers or cast coated sheets often used for covers coated on one side only. camera-ready—Artwork that has all type, line art, and graphics in place and ready to- be photographed or digitally transferred to film in preparation for making printing plates.

card stock—Also called cover stock.A stiff paper often used for postcards, catalog covers, and other items that require rigidity. Card stock is usually described by point sizes that give the thickness of the sheet in thousandths of inches. For example, io-pt card is o.olo in. thick. Card stock can also be described by pound weights based on the weight of 500 sheets measuring 20 x 26 in. each.

case binding—Casebound, or cased-in, books are typically hardbound books.The book covers, called "cases," consist of rigid or flexible boards that are covered on the outside and on the edges with cloth, leather or other material.

character generation—The process of using master font information to create type images as a series of dots or lines on a computer or typesetter. The type images can be sent either to a screen for display or to an imagesetter for final output.

characters per inch (cpi)—The number of characters that fit within a linear inch in a particular font. Standard measurement units for typewriting are pica

CIE—Abbreviation for Commission International de I' Eclairage, or International Commission on Illumination. CIE established several visual color models that have become the basis for all colorimetric measurements.

coated paper—Paper coated with clay, white pigments, and a binder.

colorant—A pigment which is the color portion of ink, toner, proofing films or paper.
color cast—An unwanted dominant color present in the original image or in its reproduction. Color cast usually results from lighting variance during photography or improper processing or proofing conditions. color electronic prepress system

(CEPS)—A high-quality, proprietary computer-based system that may include equipment for page make-up, scanning color separations, displaying color, and making color corrections. This is to be contrasted with PC-based color scanning and manipulation systems often referred to as desktop publishing systems (DTP).

color gamut—The range of colors that can be formed by all combinations of a given set of light sources or coloranis of a color reproduction system. The normal human eye can perceive a wide gamut of colors- colors within the full range of the visible spectrum, including detail in very bright light and deep shadows. Transparencies and monitors, which display color using transmitted light, can hold some of that color range, or gamut. Due to such limitations as reflected light, ink impurities, and paper absorption, a conventionally printed image is limited to a much smaller range of colors. Much of the work done in color correction arises from the tonal compression of the color gamut that occurs during color separation.

color separation—The photographic or electronic means of separating art- work into cyan, magenta, yellow, and black components.

Committee for Graphic Arts Technologies Standards (COATS)—The accredited standards development committee under ANSI responsible for graphic arts industry standards. The mission of CGATS is to have the entire scope of printing andpublishing technologies represented in one national standardization and coordination effort, while respecting the established activities of existing accredited standards committees and industry standards developers. It is charged with the overall coordination of graphic arts standards activities and the development of graphic arts standards where no applicable standards developer is available.

composite film—Also called final film. Color separations ready for plate imaging.

contacting procedure—The method of exposing a sheet of photosensitive material (graphic arts film/paper, proofing film or printing plates) by placing it in direct contact with an imaged sheet of film in a vacuum frame using a light source. This is part of the photomechanical process.

contrast—The difference of total gradation between light and dark values with in an image.A high contrast image is predominantly highlights and shadows with few gray tones. A low- Contrast image has few highlights and shadows with predominantly even tones. Image contrast is scarificied somewhat when tones are compressed to bring an orginal’s density down to a range that can be reproduced on a printing press.

contrast range—'The amount of variance between highlights and shadows in an original or reproduction.Quantified as the difference between the top highlight and deepest shadow density readings admeasured by a densitometer.

crop mark—Markings that show where a page, photograph, illustration or transparency is to be trimmed.

data compression—The translation of a computer file into a format that uses less disk space. Compressed files must be decompressed to be used. See also lossless compression and lossless compression.

desktop publishing (DTP)—The process of creating fully composed pages using a computer, off-the-shelf software, and an output device such as a laser printer.

duotone – Colour reproduction from a monochrome orginial, such as a black and white photograph. Two halftones with different screen angles are made from the same orginal and printed in two colours

dynamic range—The range of tones from lightest to darkest a scanner car see and resolve.

electron mechanicals— Digital page layout files created on a desktop publishing system. Electronic mechicals commonlv contain text and graphics in EPS, TIFF, or similar file
formats. They are a replacement for conventional paste-up boards.

embossing—Raised letters or design on paper or other material. The effect is produced by uninked dies or blocks Any colors to be used are put on first by regular printing methods.

file format—A set of instructions that describe how to store, access, or transmit digital information. Being able to match the format of data created in one program to what can be received by another is the basis for file

Fluorescence—The ability of a substance, such as paper or ink, to absorb
ultraviolet light waves and reflect them as visible light.

Fold marks—Markings at the top edge of a page showing where folds should be.

Folio—A page number.

form—The assembly of pages on a printed sheet. When folded, the form is called a signature.

Gamma—(i) In photography, The degree of contrast in an image. Film types are listed as creating certain gamma ranges appropriate to different uses. (2) In electronic color correction, the difference in the status of the color curve. The color curve represents highlight to shadow values between current values and corrected values. Changing the color curve (making a earnma correction) increases or decreases the highlights, and shadows relative to the original points on the curve.

Gloss—A shiny coating on paper. Gloss coatings allow very little ink absorption, thus providing excellent color definition -and contrast.

Grain—(i) In photography, the speckled appearance in prints or transparencies produced by clusters of silver particles in photographic emulsions. Frequently considered undesirable and apparent when an original is enlarged too much. Grain can also be emphasized for special, softening effects. (2) In paper making, the direction in which most wood pul fibers lie within the sheet due to the direction of flow as the paper is made
Folding paper against the grain break; more wood pulp fibers than folding with the grain, resulting in an uneven less precise fold.

Gray component replacement (OCR)—Also called achromatic color replacement (ACR), integrated color removal (ICR), and polychromatic color removal (PCR). Removing the
achromatic (also called contaminant or graying) component of cyan, magenta, and yellow when they all combine and replacing it with black. Gray component replacement is dis-
tinct from under color removal, which reduces process colors in only dark, neutral areas and adds black. GCR separation is done with specialized software on electronic scanners.

Gutter-The inside space between pages; that is, the inside margin toward the back or binding edger

Halftone—Ink-printable image produced photomechanically or electronically to convert a continuous tone image (for example, photograph, drawing, print, etc.) into a regular grid
pattern of various-sized dots with equidistant centers to simulate shades of gray when viewed from a normal reading distance. This reproduction method contrasts with line art (no shading of tones), mezzotints (irregular shapes in random placement), and stochastic screening (same-size microdots in a controlled random placement with in a given area)

Hard dot—A halftone dot that has hard, crisp edge without the fringe seen with the soft dot. The halftone dot also has a fairly uniform density over its entire surface.

Hue—One of the three attributes of color, the other two being saturation and brightness. Hue is determinedthe color's dominant wavelength in the visible spectrum.

Hue error—Characterizes colorant used as process colors. Expressed as percentage, hue error indicates the deviation from a theoretically perfect process hue. It does not, however, indicate any error or problem with

imagesette-A general term used for devices that generate graphic arts films or plates from electronic data sources.

imposition—Arrangement of pages so they print correctly on a press sheet and the pages are in proper order when the sheet is folded.

impression—The result of one cycle of a plate cylinder on a printing press.

Inserts—Extra printed pages inserted into printed pieces.

interleaves—Extra blank pages inserted loosely into printed pieces. Institute of Electrical andElectronic Engineers (IEEE)—An international society that issues its own standards and is a member of ANSI and ISO.

International Federation of Publishers Press (FIPP)—The group in Europe responsible for creating specifications for magazine color proofing and printing.

International Organization for Standardization (ISO)—A worldwide federation of national standards bodies from over 100 countries. Its mission is to promote the develop-
ment of standardization and related activities in the world with a view to facilitating the international exchange of goods and services, and to developing cooperation in the spheres of intellectual, scientific, technological and economic activity. The ISO Technical Committee responsible

Kelvin (K)—A thermometric scale used to measure light temperature. o°K is absolute zero (a hypothetical temperature representing the complete absence of heat); water freezes at 273•rgdK, which is o°C or 32bF, The most common use of Kelvin temperatures in the graphic arts is to describe lighting sources for viewing and analyzing color. The color of light source is measured in Kelvin temperatures. standard balanced light source (neutral in hue and with the brightness of midday sunlight) measures 5000K.

knockout—When type or line art is to be printed over a photograph or other variable color background, the best way to produce a consistent color is to first reverse the type or
artwork out of the background and then drop in the desired color.

Laser—Abbreviation for light amplification by stimulated emission of radiation. The amplification of only one frequency of light within the spectrum to create a directional, intense beam. The beam has a very narrow bandwidth capable of producing images through electronic impulses.

lossless compression—Data compression methods that rearrange or re-code data in a more compact fashion and lose no information when decompressed. Because all data are preserved, there is a distinct limit to the amount of compression that can be achieved (for example, 3:1 o' 511), See also data compression and compression .

lossy compression—Data compression methods (for example, JPEG) to selectively discard repetitive information to decrease file sizes. Depending on the amount of compression requested, the lost information may or may not be noticeable. At rates of ZS:I, the results are easily seen. See also data compression and lossless compression.

Make ready—Al so called set up.All work done on a printing press before running a job. Make ready include adjusting the plate, feeder, gripp( side guides; putting inks in the fountains; registration; and matching printed result to the supplied proof (bringing it up to color). For short runs of a few thousand, the make ready costs are a significant percentage of the total printing costs.

Matte—A coated paper finish that is not shiny like a gloss, but still keeps much -of the ink from being absorbed by the paper and provides an excellent image. Matte stocks are used commonly by book publishers.

Mechanicals—Commonly used to designate the paste-up boards that camera-ready artwork is mounted on. A second layer, often a sheet of acetae, contains the photographs or transparencies mounted in position A sheet of tracing or other semitransparent paper is often attached an includes special information or instructions; for example, make this type blue or that logo red.

Metamerism—The phenomenon that results when the color of two object to match under one lighting condition and not under another.

Moire—An undesirable optical pattern that happens when two or more grid patterns overlap, such as the halftone dots produced by an angled screen. A moire pattern may also occur when a pattern in the artwork such as a herringbone weave or window blinds, interferes with a halftone dot pattern. Manipulating artwork when scanned or using stochastic screening may eliminate the more moiré.

Nanometer—One-billionth of a meter. The wavelengths of electromagnetic energy, which includes visible light, is measured in nanometers.

Newton's rings—Irregularly shaped patterns, similar to oil on the surface of water, that appear in a color separation. They are caused by the varying amounts of air between the scanning cylinder and transparency surfaces they come into contact. The light refracts into a rainbow pattern as it passes from the cylinder through the air pockets to the transparency. This is avoided by applying a coat of oil (make airless contact) or a thin mist powder (to prevent any contact) between the two surfaces.

nonrepro blue—Also called nonphoto blue. A light blue color often used to make crop marks or notes on mechanicals.

Output—Processed optical or electronic data transferred to another device such as a secondary storage unit, a laser printer, an electronic manipulation station, or an analog or digital proofing device.

off-press proof—A four-color proof generated before the production press run and before, or instead of, a press . proof. An off-press proof can be produced photo mechanically, electro statically, or electronically.

offset lithography—A printing method that uses the repellent properties of oil and water to reproduce an image on a flat surface that contains both the image and non-printing areas. The process originated with the practice of drawing on stones (lithography comes from the Greek for "stone writing") with an oil-based crayon and then wetting the stone.
Oil-based ink would then be applied, repelled by the water, and transferred to a sheet of paper pressed upon it.

Lithographic plates are dampened with water that is repelled by the image area. Ink is then applied to the image area by ink rollers. An intermediate blanket cylinder picks up and transfers the ink image from the plate to the paper. The intermediate blanket cylinder is why this process is called offset. The bulk of publication and commercial printing is done by the offset method.

Orthochromatic—Referring to a film that is sensitive to two colors of light. Panchromatic film is sensitive to all colors of light.

Perfect binding—A binding method where the binding edge of a book or magazine is ground down about i/8 in and coated with a fast-drying glue. Then, a flexible cover is attached,creating a squared-off backbone.

Photomechanical process— The image reproduction process that involves photosensensitive imaging products (paper, film, proofing materials and plates) that react to light. During the photomechanical process these materials are imaged using a contacting procedure.

Pica—A typographic measurement. There are 12 points to a pica and approximately 6 picas to an inch.

PICT—A common data format for graphics popular with illustrations encoded on the Macintosh. PICT data can be created, displayed on the monitor, and printed.

Pixel—Abbreviation for picture element. The smallest unit that can be sensed, manipulated, or output by a digital system or displayed on a computer screen. More pixels per 'inch mean better resolution.

Plate—Reproduction of type and images on metal, plastic, rubber, or other material to form a printing surface.

Point—(i) In measuring type, i point is 1/12 of a pica or 1/72 of an inch. In other words, there are 12 points to a pica and 72 points to an inch. (2) In measuring the thickness of heavy paper stock such as bristol board, a point is 1/iooo of an inch. Thus, io-pt stock is io/looo, or o.oio in.

Porosity—The open or closed characteristics of a paper's surface that allows air to pass through and ink to penetrate. Generally, coated papers have very closed surfaces, low porosity, and hold ink on the surface well.Some papers used for blow-in cards are porosity rated for indery use.

PostScript*—A page description language for medium- to high-reso1ution( printing devices. Consists of a specific set of software commands and protocols that form images on output printers and film recorders when translated through a raster image processor. The key feature of PostScript is device independence, allowing different output devices fr
different manufacturers, which ma) not be compatible through any other means, to print the same file in more or less the same way.

Random proof—Also called first submits, scatters, or loose proofs. A press proof or off-press proof of unstripped images. Generally the first proof to be evaluated, a random proof can be used for preliminary color OKs and color correction.

Raster image process (RIP)—The process of interpreting a page description language, such as PostScript, to a raster format at the resolution and in the format required for a specific output device or image- setter. The RIP may also incorporate machine-specific instructions, and the RIP may occur either in the imagesetter or in a separate computer system.

Rregistration—Also called register. Two or more images positioned in predetermined alignment. Out of registration refers to an element reproducing slightly above or to the side of the matching one underneath it.

Registration marks—Marks outside the main image area on hard-copy or electronic mechanicals and film that help keep film mechanicals (flats), plates and printing in register.

Resolution (res)—The degree of image sharpness that can be reproduced by a piece of equipment. Resolution is measured in dots per inch (dpi), or pixels per square millimeter. On high-end scanners,resolution is counted both vertically and horizontally; for example, res 12 is counted as 12 x 12144 Pixels persquare millimeter. Desktop publishing equipment usually measures resolution in dots per dpi; for example, a 300 dpi printer. The higher the resolution, the better the image detail appears and the larger the file becomes,requiring more computer memory and longer processing times.printing where the stiffness of card stock is not required.

Text Stock – Paper stock used for the pages of reports, books and other printing where the stiffness of the card stock is not required .Text stock is described by pound weight deter-mined by the weight of 500 25 x 38 in.sheets. For example, 500 sheets of 8o-lb. text stock cut 25 x 38 in. weigh 80 pounds (standard US text pound).

Thermal dye sublimation—Also called thermal dye diffusion transfer, or D2?2. Digital proofing technology that vaporizes solid process pigments with either a heated print head or a laser beam and floats them onto a special stock where they become solid again.

Thermal wax transfer—Digital proofing technology that fuses process colored wax from a ribbon by heating it with pinpoint print heads and melting it onto a special stock.

Tolerance—The acceptable range of error from a measured standard.

Tone compression—Reduction of an original tonal range to a tonal range achievable through the reproduction process.

Touch plate—An additional printing plate that adds a matched color to a process color image.

Transparent copy—Products such as color transparencies or positive film, viewed by light passing through them, as opposed to reflective copy.

Transpose—To exchange the position of a letter, word, or line with another letter, word, or line.

Trapping—A technique in which abutting colors are slightly overlapped to minimize the effects of misregistration of the printing plates. (2) On a press, the way various color of ink adhere to one another when wet vs. the way one layer of ink adheres to

Uncoated paper—Paper that has not had a final coating applied for smoothness. Uncoated paper is absorbent and soft in appearance.

under color removal (UCR>-Reducing the cyan, magenta, and yellow inks independently within the darkest neutral shadow areas in an image reproduction and replacing them with a controlled amount of black to reduce the total tonal density. The three colors are reduced so the shadows have better detail, improved trapping, and more consistent reproduction.

unsharp masking—A function of the scanner of image editing software that increases the overall contrast at the edges of density or color changes by exaggerating the differences. In the scanner or color manipulation work- station, the computer reads the digital signals to locate where the color changes occur and then adjusts the tones and colors to create a more sudden change. If carried to an extreme, the exaggeration can result in an outline effect between some colors. During photographic color correction procedures, an unsharp mask simultaneously compresses the tones and makes the corrections. In either case, unsharp masking, despite its name, globally increases the detail

value—See brightness.

varnish—A clear, liquid, resinous coating, either matte or glossy, that is applied to a printed product for protection and appearance.

vignette—Color manipulation effects in which all or a portion of an image fades gradually away until it blends into the non-imaged area. Sometime! used to refer to a graduated back- ground tone.

viscosity—Thickness or thinness of a fluid as measured by its resistance to flow. Ink viscosity is adjusted to maintain a proper flow through the ink train of a press and on to the paper.

visible spectrum—That portion of the electromagnetic spectrum to which the human eye is sensitive; wave-lengths of approximately 400 through 700 nanometers. Due to the characteristics of cone sensing (color reading mechanism of the retina), it is generally agreed that humans detect only red, green, and blue. All perceived colors are combinations of those sensitivities (hue) in relation to the strength of the transmitted or reflected light (brightness) and the intensity of the light hitting the retina (saturation). Ultraviolet wavelengths are shorter and infrared wavelengths are longer than the sensitivity range of the eye.

web press—A press that prints image on rolls of Paper.