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PrePress Glossary
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C D E F G H I J K L M
N O P Q R S T U V W X Y Z |
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- Aliasing (jaggies)
- Visibly jagged steps along angled lines, or object edges
due to sharp tonal contrast between pixels.
- All signature folding dummy
- A folding dummy in which all of the signatures that make
up the job are used to determine the page arrangement for each signature. Also known as a
Job Worksheet.
- Bindery marks
- Marks that appear on a press sheet to indicate how the sheet should be cropped, folded,
collated, or bound.
- Bit
- A computer's smallest unit of information. Bits can have only two values: 0 or 1.
- Bitmap Image
- An image constructed from individual dots or pixels set to a grid-like mosaic. Each
pixel can be represented by more than one bit. A 1-bit image is black and white because
each bit can have only two values (for example, 0 for white and 1 for black). For 256
colors, each pixel needs eight bits (2 8 ). A 24-bit image refers to an image with 24 bits
per pixel (2 24 ), and so may contain as many as 16,777,216 colors. Because the file must
contain information about the color and position of each pixel, the disk space needed for
bitmap images is usually quite significant. Most digital photographs and screen captures
are bitmap images. A digitized image that is mapped into a grid of pixels. These types of
images cannot be enlarged or printed at higher resolutions without developing jagged edges
(aliasing/pixelization).
- Bleed
- Text or art that extends beyond the trim page boundaries, or the crop marks, on one or
more sides of a page. An extra amount of image that extends beyond the trim-edge of the
page.
- Blend
- See Graduated fill.
- Cab
- See Flat.
- Calibration bars
- A strip of varying shades usually ranging from 0% to 100% (in 10% increments) on film,
proofs, and press sheets. Prepress service providers use calibration bars to measure and
control screen percentages for printing and proofing.
- Camera Ready
- Reflective artwork that needs to be shot with a copy camera to transfer to negative
film.
- Center marks
- Press marks that appear on the center of all sides of a press sheet to aid in
positioning the print area on the paper.
- Choke & Spread (trapping)
- The process of creating a slight overlap between adjacent colors (called a trap) in
order to keep the paper color from showing through.
- CMYK
- Acronym for cyan, magenta, yellow, and black, the four process color inks which, when
properly overprinted, can simulate a subset of the visible spectrum. See also color
separation. Also refers to digital artwork that contains information necessary for
creating color separations.
- Color overlay
- A sheet of film or paper whose text and art correspond to one spot color or process
color. Each color overlay becomes the basis for a single printing plate that will apply
that color to paper.
- Color proof
- A representation matching the appearance of the final printed piece. Includes color
laser proofs, color overlay proofs, and laminate proofs.
- Color separation
- The process of transforming color artwork into four components corresponding to the four
process colors. If spot colors are used, additional components may be created containing
only those items that will appear in the corresponding spot color layer. Each component is
imaged to film or paper in preparation for making printing plates that correspond to each
ink.
- Combination signatures
- Signatures of different sizes inserted at any position in a layout.
- Composite proof
- A version of an illustration or page in which the process colors appear together to
represent full color. When produced on a monochrome output device, colors are represented
as shades of gray.
- Creep
- The movement of a press sheet while traveling through a press. Sometimes associated with
shingling.
- Crop marks
- Short, fine lines used as guides for final trimming of the pages within a press sheet.
- Custom printer description file
- A file containing information specific to a type of output device; used in conjunction
with a standard PPD file to customize the printing process.
- DCS
- Acronym for Desktop Color Separation, a version of the EPS file format. DCS 1.0 files
are composed of five PostScript files for each color image: cyan, magenta, yellow, and
black file, plus a separate low-resolution FPO, image to place in a digital file. In
contrast, DCS 2.0 files can have a single file that stores process color and spot color
information.
- Defining Color
- The color, usually the darker color, whose shape defines the object. The defining color
should not be choked or spread, as that would compromise the image.
- Densitometer
- A device used throughout the printing process to measure the amount of light passing
through or reflecting from a given medium.Die line In a digital file, the outline used to
create a device for cutting, stamping, or embossing the finished printed piece into a
particular shape, such as a rolodex card.
- Dot Gain
- When an ink dot enlarges through absorbtion on a porous paper. This affects the overall
tone of an image, as the size of the dot is equivalent to the tone it represents.
- Down-sampling
- The reduction in resolution of an image, resulting in a loss of detail.
- DSC
- Acronym for Document Structuring Conven-tions, a set of organizational and commenting
conventions for PostScript files designed to provide a standard order and format for
information so applications that process PostScript, such as Imation PressWise(TM), can
easily find information about a document's structure and imaging requirements. These
conventions allow specially formatted PostScript comments to be added to the page
description; applications can search for these comments, but PostScript interpreters
usually ignore them. Imation TrapWise(TM) requires that the PostScript in incoming files
is formatted using conventional DSC comments, so certain functions may not work if the
file is not DSC-conforming.
- Duotone
- A halftone that is printed as a two-color image by replicating a portion of the original
tonal range for the second color. The halftone screens must be angled 30 degrees apart.
- Emulsion
- The light-sensitive coating on film or photo-graphic paper.
- EPS
- Acronym for encapsulated PostScript, a single-page PostScript file that contains
grayscale or color information and can be imported into many electronic layout and design
applications. Encapsulated PostScript. A standard file format that allows vector
and bitmap graphics, as well as page layouts, to be placed into other documents. EPS files
cannot be manipulated, and need to be trapped in the parent program.
- Film assembly
- See Stripping.
- Final Size
- The size of the printed piece after folding and any
finishing work.
- First signature folding dummy
- A folding dummy that determines the page arrangement for
a single signature layout template. This template can then be applied to a job that
requires multiple signatures, and PressWise will correctly impose all the pages based on
the numbering sequence and binding method specified by the first signature.
- Flat
- Individual film assembled onto a film carrier readied
for contacting or platemaking. Referred to as a cab in gravure printing.
- Flat Size
- The size of the printed piece before folding.
- Flexographic printing
- Printing on a press using a rubber plate that stretches
around a cylinder, making it necessary to compensate by distorting the plate image.
Flexography is used most often in label printing, often on metal or other non-paper
material.
- Flood
- A user-defined, screened box that prints on and
completely covers a PressWise blank page.
- Folding dummy
- A template used for determining the page arrangement on
a form to meet folding and binding requirements. See also All signature folding dummy and
First signature folding dummy.
- Folio
- A printed page number.
- Form
- In PressWise, the front or back of a signature.
- FPO
- Acronym for For Position Only, a term applied to
low-quality art reproductions used to indicate placement and scaling of an art element on
mechanicals or camera-ready artwork. In digital publishing, an FPO can be low-resolution
TIFF files that are later replaced with high-resolution versions. An FPO is not intended
for reproduc-tion but only as a guide and placeholder for the prepress service provider.
- GCR
- Abbreviation for gray component replacement, a technique for minimizing ink coverage.
When TrapWise converts RGB data to CMYK, it analyzes a bitmap image for gray tones
composed of cyan, magenta, or yellow and replaces those colors with a similar percentage
of black.
- Gradient fill
- See graduated fill.
- Graduated fill
- An area in which two colors (or shades of gray) are blended so as to create a gradual
change from one to the other. Graduated fills are also known as blends, gradations,
gradient fills, and vignettes.
- Gray component replacement
- See GCR.
- Grayscale
- The representation of colors in varying shades of gray¬usually 256 shades in digital
artwork.
- Grind-off
- The trim at the back (or spine) of a signature, or of two or more gathered signatures,
in prepara-tion for perfect binding.
- Gripper edge
- The leading edge of a sheet of paper, which the grippers on the press grab to carry the
paper through a press.
- Gutters
- Extra space between pages in a layout. Gutters can appear either between the top and
bottom of two adjacent pages or between two sides of adjacent pages. Gutters are often
used because of the binding or layout requirements of a job ¬for example, to add space at
the top or bottom of each page or to allow for the grind-off taken when a book is perfect
bound.
- Halftone
- The reproduction of continuous-tone artwork (such as a photograph) through the
application of a screen that converts the image into dots of various sizes. (See the
resolution section in the Building Electronic File Module)
- Hightlight & Shadow Detail
- In a halftone, the image detail at either end of the tonal range that is difficult to
hold when printing. Highlights often get "blown out" (lost) and the shadow
detail often gets "plugged" (filled in). You can control this by preparing your
halftones for the specific paper stock used. See the Inkworks Scanning specs for details
on preparing your halftones appropriately.
- Imagesetter
- An output device using photosensitive paper or film and achieving high
resolution. A photographic device that interperets the postscript description of a page
through its Raster Image Processor (RIP) to image the graphical data directly onto film.
- Imaging
- The process of producing a film or paper copy of a
digital file from an output device.
- Imposition
- The layout of pages in the position they will be printed on
the press-sheet. The process of arranging
individual pages on a form to construct a signature so the pages will be in proper
sequence after printing, folding, and binding.
- Imported Graphics
- Graphics and photos that are created in one program, such as Adobe Illustrator, and
imported into another, such as Quark Xpress, for final output.
- Interpolation
- The computer's way of increasing image resolution by filling
in new pixels. The pixels' color or tonal range are based on neighboring pixels.
- Job state
- The state of working in PressWise while one or more jobs are open. Opposite of no-job
state.
- Keyline
- A thin border around a picture or a box indicating where to place pictures. In digital
files, the keylines are often vector objects while photographs are usually bitmap images.
- Knockout
- A printing technique that prints overlapping objects without mixing inks. The ink for
the underlying element does not print (knocks out) in the area where the objects overlap.
Opposite of overprinting.
- Line Art
- Art that is made up of continuous lines such as pen & ink drawings or typefaces.
There is no tonal difference from one area to another.
- Line Screen (lpi)
- The number of lines or spots per inch on a halftone screen. (See the resolution section
in the Building Electronic File Module.)
- Misregistration
- The unwanted result of incorrectly aligned process colors and spot colors on a finished
printed piece. Misregistration can be caused by many factors, including paper stretch and
improper plate alignment. Trapping can compensate for misregistration.
- Mockup
- In PressWise, a proof used to ensure the correct page numbers, orientation, and
dimensions are used in the final printout of an imposition layout. A PressWise mockup does
not include any of the text or graphics of the imposed page.
- MoirČ
- An undesirable pattern created when overlapping screen angles are incorrect. Screens
should be at 30 degree angles to each other.
Multiple-up layout
See Step-and-repeat.
- Neutral density
- A measurement of the lightness or darkness of a color. A neutral density of zero (0.00)
is the lightest value possible and is equivalent to pure white; 3.294 is roughly
equivalent to 100% of each of the CMYK components.
- No-job state
- The state of working in PressWise while no jobs are open. Opposite of Job state.
- Object oriented art
- Vector-based artwork composed of separate elements or shapes described mathematically
rather than by specifying the color and position of every point. This contrasts to bitmap
images, which are composed of individual pixels.
- OPI
- Acronym for Open Prepress Interface, a set of PostScript language comments developed by
Aldus Corporation for defining and specifying the placement of high-resolution images in
PostScript files on an electronic page layout.
- Output device
- Any hardware equipment, such as a laser printer or imagesetter, that produces text or
graphics created on a computer.
- Overprint
- A printing method that prints one ink on top of another ink. In overprinting, the
combination of inks combine to make a new color. The opposite of knockout.
- PICT
- A file format for both object oriented graphics and bitmap images.
- Pixel
- Abbreviation for picture element, one of the tiny dots generated by a computer or output
device to constitute images.
- Posterization
- An effect that is achieved by converting an image with continuous tonal range (such as a
photo) to one with a limited number of visible steps/bands.
PostScript
A device-independent page description language developed by Adobe Systems, Inc.
PostScript Printer Description file
See PPD.
PPD
Acronym for PostScript Printer Description, a file format developed by Adobe Systems,
Inc., that contains information enabling software to produce the best results possible for
each type of designated printer.
Prepress service provider
In the publishing industry, the generic term for color separation houses, commercial
printers, electronic prepress houses, service bureaus, and in-plant printers.
Press sheet
In sheet-fed printing, the printed sheet of paper that comes off the press.
Printer's marks
The marks printed on a press sheet or film to aid in positioning the print area on the
press sheet, checking the quality of the printed image, and trimming the final pages.
Printer's marks may include calibration bars, crop marks, and registration marks.
Printer spread
A pair of pages positioned across a fold from each other on the press sheet.Process
colors The four transparent inks (cyan, magenta, yellow, and black) used in four-color
process printing. See also Color separation.
Printer Font
The part of a postscript font that defines the shape of the font for the postscript
printer, e.g., an imagesetter or laser printer.
Printer Spreads
When the pages are ordered as they will print, rather than how they will be read. This
relationship is determined by the amount of pages in the document, and the sheet size they
will be run on.
Process color
Color created by the subtractive primaries, yellow, cyan, magenta and black inks in
order to create the appearance of the a full-spectrum of colors. Often refered to as
"four- color process".
Punch calibration file
A PressWise file containing the center punch hole locations of specific imaging devices.
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- Rasterize
- The process of converting digital information into pixels. Also the process used by an
imagesetter to translate PostScript files before they are imaged to film or paper. See
also RIP.
- Reader spread
- A layout made in two-page spreads as readers would see them. For example, an 11 by 17
reader's spread of a 16-page manual would have pages 2 and 3 next to each other and so on.
- Recto page
- The right-hand page of an open book or spread. Opposite of verso page.
- Reflective Art
- Artwork that must be photographed from light reflected from its surface. Generally used
as camera ready art.
Registration marks
Figures (usually crossed lines and a circle) placed outside the trim page boundaries in
color separation overlays to provide a common element for proper alignment.
Resolution
The density of graphic information expressed in dots per inch (dpi) or pixels per inch
(ppi).
RGB
Acronym for red, green, blue, the colors of projected light from a computer monitor
that, when combined, simulate a subset of the visual spectrum. Also refers to the color
model of most digital artwork. See also CMYK.
RIP
Acronym for raster image processor, the part of an output device or imagesetter that
converts digital information into dots on film or paper. See also Rasterize.
- Screen Font
- The part of a postscript font that defines how to draw the font cleanly (not bitmapped)
on the monitor.
- SEP
- A PostScript file format created from PageMaker (TM) that can contain multiple pages as
well as links in the form of OPI comments to high-resolution images, in color or in black
and white.
Separation
See Color separation.
Sheet side guides
Printer's marks that appear along each side near the bottom of a press sheet to aid in
positioning the print area on the press sheet.
Sheetwise layout
A layout in which different plates are used to print the front and back of a press
sheet. Sheetwise layouts are used for creating book signatures for multiple-page
documents.
Shingling
An adjustment for the way page images in a folded signature tend to move toward the
outer or facing edge of a book. The amount of shingling needed steadily increases as you
move toward the center signatures in the book.
Signature
A completed press sheet, before folding, collating, binding, and trimming.
Spot color
Any premixed ink that is not one of or a combination of the four process color inks.
Step-and-repeat
A layout in which two or more copies of the same piece are placed on a single plate.
This is useful for printing several copies of a small layout, such as a business card, on
a single sheet. Also called a multiple-up layout.
Stripping
The act of assembling individual film negatives into
flats for printing. Also referred to as film assembly.The final positioning of film
negative pages onto a goldenrod flat prior to plate making.
- TIFF
- Acronym for Tagged Image File Format, a file format developed by Aldus, Microsoft (TM),
and leading scanner vendors for bitmap images containing grayscale or color information.
An image file format that is supported by the majority of image-editing programs, running
on a wide variety of computer platforms.
Tints
Various even tone areas (strengths) of a solid color. Created by converting the area to
a set dot size.
Tonal Curves
These curves are used to adjust smoothly the tonal range of a scanned image. Curves can
be adjusted for the overall image, a selected portion of the image, or individual color
channels (CMYK). See the Scanning section for more information.
Trapping
The process of creating an overlap between abutting colors to compensate for imprecision
in the printing process. Trim page size Area of the finished page after the job is
printed, bound, and trimmed.
TRP
A file extension indicating that a file has been trapped in TrapWise.
- UCR
- Abbreviation for under color removal, a technique for minimizing ink coverage. When
TrapWise converts RGB data to CMYK, it analyzes a bitmap image for excessive cyan, magenta
or yellow in dark areas and replaces those colors with a similar percentage of black.
- Unsharp Mask
- A filter in Adobe Photoshop used to make an image look crisper. The filter identifies
where two tones adjoin and increases the contrast. The user can control the amount of
contrast applied and the amount of pixels affected.
Under color removal
See UCR.
- Vector objects
- Artwork or text characters constructed from mathematical statements instead of
individual pixels. Vector objects usually take less disk space than bitmap images and can
be scaled to virtually any size without losing visual quality. Fonts (such as PostScript
and TrueType), illustrations from drawing applications, and files from page-layout
applications are common examples of vector objects.
- Verso Page
- The left-hand page of an open book or spread. Opposite of recto page.
- Vignette
- See graduated fill.
- Visual Neutral Density
- The degree to which a color is perceived to be light or dark. Prepress service providers
measure visual neutral density using a densitometer with no process filters.
- Work-and-tumble layout
- A layout in which a single plate is used to print both sides of a two-sided job. The
paper is run through once, then flipped over, top to bottom, to run on the opposite side.
The gripper edge changes from the edge that was the head on the first pass to the edge
that was the tail.
- Work-and-turn layout
- A layout in which a single plate is used to print both sides of a two-sided job. The
paper is run through once, then flipped over, side to side, to run on the opposite side.
Both sides use the same gripper edge to hold the paper for positioning, and
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