Imperial Printing | Glossary of Terms

A B C D E F G H I J K L M O P R S T U V W

A

Additive Primary Colors - Red, green and blue (RGB) which are the three colors used to create all other colors when direct, or transmitted, light is used (for example, on a computer monitor). They are called additive primaries because the blending of these three colors reflects all color and produces white.

ASCII - An acronym for American Standard Code for Information Interchange. A standard that assigns a unique binary number to each text character and control character. Note that special characters may not be transferred correctly when converting text across platforms and fonts.

B

Balance - The adjustment between water and ink on a printing press that maximizes the amount of ink transferred to the paper.

Bit - A contraction of binary digit. The smallest unit of information used by a computer. The value of a bit (0 or 1) represents two alternatives, such as on or off, true or false, black or white, etc.

Bitmap - A set of bits that represents the graphic image of a document. Used by MacIntosh to construct some low resolution graphic images and fonts.

Browser - A program used to view sites on the World Wide Web.

Byte - A unit of information consisting of a fixed number of bits. One byte usually consists of a series of eight bits, and represents one character (such as a letter, numeral, or punctuation mark).

C

Calibration Bars - The printed 11-step grayscale wedge that appears on printed output. When you print a CMYK color separation, this step wedge appears only on the black plate. On a color image, this refers to the color swatches outside the image area that are measured for density thus ensuring consistency.

Case Binding - A binding process that applies a hard cover.

CMYK - The four process colors of cyan, magenta, yellow and black used to print color images.

Computer to Plate (C-T-P) - A process that images directly to a printing plate without the necessity for film.

Continuous Tone Image - An image containing gradient tones from white to black including gray tones. This is the format of original film photographs.

Crop - To select part of an image for reproduction while discarding the rest of the image.

Crop Marks - The marks that are printed near the edge of an image that line up to indicate where the image or paper will be trimmed.

D

Density - The ability of an object to stop or absorb light. The less the light is reflected or transmitted by an object, the higher the density.

Deboss - A recessed impression on a surface. The opposite of emboss.

Die (Creasing/Cutting) - Strips of metal with a blunt or sharp edge bent into the shape of the final printed piece and seated in wood.

Die (Foiling/Embossing) - An etched piece of metal with an even raised (foiling) or recessed (embossing) surface. These dies can be made from magnesium, steel, copper or brass.

Die (Multi-level) - An embossing die generally hand etched in brass that creates various levels in an embossed product.

Dot Gain - A limitation of the printing process that causes dots to print larger than they should and creates darker tones or colors.

DPI - Dots per inch. A measure of resolution.

Duotone - The replacement of a number of dots in a halftone with a secondary color.

E

Emboss - A raised impression on a surface. The opposite of deboss.

Emulsion - The photosensitive layer on a piece of film or paper.

Encapsulated PostScript (EPS) - A file format that describes a document and contains all the code necessary to print a file.

F

Flash - A website design tool used to create and animate vector art. The user requires a Flash plug-in to view these sites. See also Plug-In.

Flat Sheet Printing - A type of printing that utilizes individual sheets of paper. Compare Web Printing.

Flood Varnish - The application of varnish to the entire sheet. Compare Spot Varnish.

Foil - The application of a thin colored metal instead of ink.

Folio Sheet - The master size of a family of paper, such as bond, text or cover, used to calculate the Sub Weight. See also Sub Weight. Compare Parent Sheet.

Font - A collection of letters, numbers, punctuation marks, and other typographical symbols with a name and consistent appearance. Usually includes a complete family appearing in different weights and styles such as bold, italic, small caps, etc.

FTP - An acronym of File Transfer Protocol that is used to move large files over the internet.

G

Gang - The impositioning of a number of jobs on one sheet when ink colors and paper are the same to benefit from shared set up costs.

Gatefold - The folding of the right and left edges of a sheet to meet in the center and produce a barn door-like effect.

Ghosting - The undesirable appearance of a faint image from another part of the printed area.

GIF – An acronym of Graphic Interchange Format that provides images of 8 bits or less for use by web browsers.

Graduation - A change in density achieved through a uniform increase or decrease in shading.

Grayscale Image - A single channel image consisting of up to 256 levels of gray with 8 bits of information per pixel.

Gray-Component Replacement (GCR) - The removal of a mixture of cyan, magenta and yellow and the replacement of them with black. Similar to undercolor removal (UCR), but is generally more extreme and uses more black.

Grip - The unprinted margin required by a flat sheet printing press for pickup of paper. Compare Plate Gap.

H

Halftone - A process of representing a continuous tone image (e.g., a photograph) by converting the various shading and colors into a uniform pattern of various size dots. Compare Stocastic Screening.

Hickey - The undesirable appearance of a dot surrounded by a halo in a solid printed area. Caused by a small piece of debris.

Highlight - The lightest part of an image represented in a halftone by the smallest dots or the absence of dots.

HTML - An acronym of HyperText Markup Language that provides a language to describe web pages.

Hue - The main attribute of a color that distinguishes it from other colors.

I

Imposition - The placement of a single, repeated or multiple documents on a sheet to maximize paper and equipment. Creates a signature for the production of books.

J

JPEG - An acronym of Joint Photographic Experts Group that provides a 24 bit compression format for images.

K

Kern - The reduction of spacing between letters in a document.

L

Leading - The amount of spacing between lines of type as measured from baseline to baseline.

Line Drawing - An illustration that consists of a single density without shading.

Lip - An extended amount of paper on one edge of a signature that provides margin for easy separation and pickup during binding.

LPI - Lines per inch. A measure of resolution.

M

M Weight - The weight in pounds of one thousand sheets of paper in a particular size. Compare Sub Weight.

Mezzotint - A grainy textured effect applied to an image and resembling the burnishing or stippling of an engraving on copper or steel.

Midtone - The tonal values of an image between the highlight and the shadow.

Moiré - An undesirable pattern caused by incorrect screen angles when overlaying halftones during scanning or printing.

O

Offset (or Set Off) - The undesirable transfer of ink from the front of one sheet to the back of the next.

P

Pantone - A color matching system that utilizes predetermined mixing colors to achieve consistent color between printers. See also Spot Color.

Parent Sheet - A master size of paper that provides multiple sheets of standard sizes (e.g., letter) when cut. Compare Folio Sheet.

PDF - An acronym of Portable Document Format which locks and compresses the Postscript information of a file.

Perfect Binding - A binding process that uses glue to adhere the sheets to a soft cover. Generally used on thick documents.

PICT - A document format used by a number of graphics and page layout programs.

Pica - A unit of measurement containing twelve points and approximating one sixth of an inch.

Pixel - The smallest single dot capable on a computer display or in a digital image.

Plate - A sheet with the printing image used to transfer ink from the printing press to the paper.

Plate Gap - The unprintable margin between image areas required by a web printing press. Compare Grip.

Platform - The operating system of a computer used to create documents such as Mac, IBM or UNIX.

Plug-In - A file that adds functionality to a web browser. See also Browser.

Point - A unit of measurement and approximating one seventy second of an inch.

Posterization - An effect applied to an image where the hue, saturation and luminance are drastically altered to remove shading and produce a line drawing.

Postscript - A language used to describe a document mathematically so that it can be accurately reproduced at virtually any size.

Process Color - The four pigments - cyan, magenta, yellow and black - used in full color printing. Compare Spot Color.

R

Register - The alignment of various colors on a printed piece.

Register Marks (Bull’s-Eyes) - Crosshair marks that appear outside the printed image to assist in the alignment of various printing plates.

Resample - To change the resolution of an image. Resampling down discards pixel information in an image; resampling up adds pixel information through interpolation.

Resolution - The number of pixels per inch in an image or the number of dots per inch used by an output device. Resolution can also refer to the number of bits per pixel.

RGB Image - A three-channel image containing a red, green and blue channel as appearing on color monitors. Compare CMYK image.

RIP - An acronym for Raster Image Processor that interprets the printing file for a document and prepares specific hardware to receive and print the file.

S

Saddle Stitch - A bindery process that uses staples on the folded and nested spines of a document.

Saturation - The amount of gray in a color. More gray in a color means lower saturation; less gray in a color means higher resolution. In terms of ink, saturation refers to the maximum amount of pigment a substrate will absorb before pooling occurs.

Scanner - An electronic device that digitizes and converts photographs, slides, paper images or other two-dimensional images into bitmapped images. A digital camera is a scanner that converts three-dimensional objects into digital, bitmapped images.

Screen Angles - The angles at which halftone screens are placed in relation to one another.

Screen Frequency - The density of dots on the halftone screen, commonly measured in lines per inch (LPI). Also known as screen ruling.

Scumming - The undesirable effect occurring when a printing press is not in balance and producing feathering on an image and patches of ink in non-image areas.

Sepia - An effect of transforming a color or black and white image into brown tones to achieve an antique effect.

Shadow - The darkest part of an image represented in a halftone by the largest dots.

Signature - A sheet of paper alternately folded at right angles to properly sequence pages in a book.

Slurring - The undesired effect produced when a sheet slides during printing.

Spot Color - Multi-colour printing that employs the use of inks without the process color procedure. Compare Process Color.

Spot Varnish - The application of varnishes to specific areas of a sheet.

Stocastic Screening – A process of representing a continuous tone image (e.g., a photograph) by converting shading and colors into a random pattern of various size spots. Compare Halftone.

Stripping - The process of positioning film and masking non-image areas in preparation for printing.

Substrate - Any material used to retain an image.

Sub Weight - The weight in pounds of five hundred sheets of the master size of a particular family of paper (e.g., bond is 17” x 22”). Compare M Weight.

Subtractive Primary Colors - Cyan, magenta and yellow which are the three pigments that when mixed, theoretically absorb all color and produce black.

T

Thermoengraving - The application of a plastic resin to an ink that is then baked to produce a raised, glossy finish.

Trap - A small overlap of color between two adjoining images that prevents a gap from appearing due to a slight misalignment or movement on the press.

TrueType Font - A font that can be displayed or printed at any size. Also called outline font or variable size font.

U

UV Coating - An extremely durable, high gloss finish applied to a sheet and cured with ultraviolet light. See also Flood and Spot Varnish.

Undercolor Removal (UCR) - The technique of reducing the cyan, magenta and yellow inks from the darkest neutral shadow areas in an image and replacing them with black.

V

Varnish - The unpigmented vehicle of an ink used to seal an image for durability. May also contain plastics and other additives to create gloss and matte finishes. See also Flood and Spot Varnish.

W

Web Printing - A type of printing that utilizes rolls of paper. Compare Flat Sheet Printing.

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