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Definitions
A
- Adobe Ink Types:
- In PostScript language specification (definition for trapping) these are Colorant Types that control how trapping is done for a specific ink.
Can be either Normal, Transparent, Opaque or OpaqueIgnore. For instance, die-lines and varnishes can be set Transparent and metallics can be set Opaque for the purposes of trapping.
- Aliasing (jaggies):
- Visibly jagged steps along angled lines, or object edges due
to sharp tonal contrast between pixels.
- Area Trapping:
-
Selecting an area on a page and defining trapping parameters for it to create specific trapping inside that area, which is different from that on the whole page.
B
- Bitmap:
- 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:
- An extra amount of image that extends beyond the trim-edge of
the page.
- Brush:
- The shape, with which trapping line is drawn.
- Brush Size:
- The diameter of a circle brush for trapping.
- Brush Shape:
- The tip of a brush (can be round or square in I-Trap).
- Black Brush:
- The brush applied for trapping of objects that are multicolor or single color Black.
- Black Density Level:
- The value indicates the neutral density at or above which the trapping engine considers an ink to be Black.
C
- Camera Ready:
- Reflective artwork that needs to be shot with a copy camera
to transfer to negative film.
- Center Trap:
- A trapping line between two objects that spreads half width into one object and half width into the adjacent object.
- Choke & Spread (trapping):
- Choke - A type of trap created by extending the background
object into the foreground object.The process of creating a slight
overlap between adjacent colors (called a trap) in order to keep
the paper color from showing through. See also Spread.
- Contone:
- stands for continuos-tone data such as photographs or digital paintings. Technically they are called raster images and are made up of a grid of dots known as pixels. In raster images there is no notion of objects or shapes because data is represented by dots.
D
- DCS:
- DCS (Document Colour Separation) format is a type of EPS format, developed by Quark Inc for using preseparated images in the
publications. There are two versions of the format. An image in DCS 1.0 is presented in five files: four of them are CMYK channels
and the fifth is a low resolution image data to show on screen. The DSC 2.0 format supports any number of color channels and
stores all information in one file. This is one of few formats allowing to prepare full color raster images with pantone inks for
prining.
- 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.
- Density Level:
- this is an ink-based setting, which defines the amount of ink shared between two colors that must be equal to, or greater than
the density level in order for a trap condition not to exist.
- 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.
- 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.
E
- EPS:
- 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.
F
- Final Size:
- The size of the printed piece after folding and any finishing
work.
- Flat Size:
- The size of the printed piece before folding.
- Flatten Transparensy:
- Flattening reduces file size by merging all visible layers into the background and discarding hidden layers. Any transparent
areas that remain are filled with white.
G
- Gray Component Replacement:
- Gray Component Replacement is another
approach to the color replacement process, which also substitutes
CMY ink with black but over a greater color range than UCR.
H
- Halftone:
-
Halftoning is the transformation of a grayscale or color image to a pattern of small spots with a limited number of colors
(e.g. just black spots on white background), in order to make it printable. Digital halftoning uses a raster image or bitmap
within which each monochrome picture element or pixel may be on or off, ink or no ink.
- 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.
I
- Imagesetter:
- 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.
- I-LINK:
- I-Link is a technology, which allows I-Trap to output the exact same ripped-trapped data to multiple formats via different output plugins all during one pass through the Rip! I-Link can be used with either trapped or un-trapped raster data.
- Imposition:
- The layout of pages in the position they will be printed on
the press-sheet.
- 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.
- Internal Image Trapping:
- I-Trap has a special case trapping setting, which allows applying traps inside contone image data.
J
- JPEG:
- It is a raster compressed file format with quality losses used to create files for online proofing, internet, etc.
K
- Knockout:
- This term is used to define an object that prints directly to media without underlying colors. Opposite to Overprint.
L
- 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.
- LineWork:
- Same as Line Art
- LUT:
- Color look-up table used by the I-Trap Viewer and the Rip trapping plugin. The table is updated with the spot colors when a job is processed through the Viewer. It contains CMYK equivalents for inks and all ink based trapping parameters controlling trapping decision, direction and color in Lucid trapping engine.
M
- Moire:
- An undesirable pattern created when overlapping screen angles
are incorrect. Screens should be at 30 degree angles to each other.
- Miter Trapping:
- Creating special shapes when trapping object's corners.
N
- Neutral Density:
- Represents a measure of how dark the color is. The lightest possible value corresponds to a neutral density of 0.0 and is equivalent to pure white; while the value 3.294 is roughly equivalent to the sum of 100% of each of the CMYK inks and can be interpreted as Registration Color.
- Neutral Preset:
- There are three commonly used collections of Neutral Density values for process inks known as SWOP, EURO and TOYO.
- No Trap Level:
- The amount (intensity or coverage) of an ink that can be considered white for the purposes of trap condition calculation.
White color does not need to trap to other colors, except for registration marks.
O
- Opaque:
- See "Adobe Ink Types" description.
- OpaqueIgnore:
- See "Adobe Ink Types" description.
- Overprint:
- This term is used to define an object that prints over another object(s). Opposite to Knockout.
The order in which inks are printed, as well as variations in the inks and paper, can significantly
affect the final results. For example, when you print a cyan ink over a yellow ink, the resulting overprint color is green.
P
- PDF:
-
Portable Document Format (PDF) is a flexible, cross-platform, cross-application file format. Based on the PostScript imaging model, PDF files accurately display and preserve fonts, page layouts, and both vector and bitmap graphics. In addition, PDF files can contain electronic document search and navigation features such as electronic links.
- 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.
- Pre-Separated:
-
The jobs that present each ink in separate file.
- 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".
- PS:
-
PostScript Adobe® is a page description language and programming language used primarily in the electronic and desktop
publishing areas. With PostScript becoming a de-facto standard for printed output, it was natural to consider using the same
language for describing the screen output as well. PostScript programs typically are not produced by humans, but by other
programs. Interpreters of PS language are called raster image processors (RIP).
Q
R
- Reflective Art:
- Artwork that must be photographed from light reflected from
its surface. Generally used as camera ready art.
- Remapping:
-
Replacing of one ink in a job with another ink or converting a spot ink to its CMYK equivalent.
- Resolution:
- The number of pixels along the height and width of a bitmap image is called the pixel dimensions of an image.
The number of pixels per inch (ppi) printed on a page determines the image resolution.
- RIP:
-
Raster image processor (RIP) is used to interpret PS, PDF and other file formats and create raster output data of needed formats to files or to drive hardware output devices such as plotters, imagesetters, etc.
- RIP Queue:
-
A collection of the RIP Page setups and Input channels that allow a job to process automatically through several devices.
S
- Screen Font:
- The part of a postscript font that defines how to draw the font
cleanly (not bitmapped) on the monitor.
- Separations Style:
-
This is the RIP setting dialog where you can define ink based parameters for screening and output.
- Spread (Trapping):
- A type of trap created by extending the foreground object into
the background object.
- Spool Folder:
-
The folder that is monitored by an application to collect and process jobs (files) copied to that folder.
- Stripping:
- The final positioning of film negative pages onto a goldenrod
flat prior to plate making.
- Solid Ink Reduction Level:
-
The %% of solid ink used in trap color.
- SuperBlack:
-
Same as multicolor Black.
- SWOP:
-
This is one of the common predefined set of Neutral Density values for process inks.
T
- TIFF:
- Tagged-Image File Format (TIFF, TIF) is used to exchange files between applications and computer platforms. TIFF is a
flexible bitmap image format supported by virtually all paint, image-editing, and page-layout applications. Also, virtually
all desktop scanners can produce TIFF images.
- Tints:
-
Various even tone areas (strengths) of a solid color. Created
by converting the area to a set dot size.
- TIO:
-
Trap Instruction Object - a collection of trapping parameters for a page, job.
- 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).
- TrapSet:
-
A collection of trapping parameters for the Lucid trapping products presented as a TIO file for use with trapping plugin in the RIP.
- Trap-on-Fly:
-
Lucid technology in the Viewer to apply traps to a selection of the source page and display the trapped result immediately (WISIWIG type of responce).
- Trap Areas:
-
Areas created on a page to apply specific trapping parameters and achieve different trapping results for different parts of the page.
- Trap Color:
-
The color of a trapping line.
- Trap width:
-
The width of the trapping line.
- Trapping:
-
Trapping is accomplished by intentionally overlapping colors
so that minor problems with alignment are not noticed.
- Transparent:
-
Transparent object allows to show what is printed underneath it. See "Adobe Ink Types" description for this term in Lucid Trapping product.
- T-RLE:
-
A run-length type compressed raster image format internally used in Lucid trapping software to store data.
U
- 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.
- Undercolor Removal (UCR):
- Undercolor Removal is a technique in color printing for reducing
the amount of cyan, magenta and yellow ink in shadows and neutral
areas of an image and replacing them with an appropriate amount
of black. This reduces the total area of ink coverage (TAC), which
is defined as the sum of dot percentages of all four inks (CMYK)
that contribute to a printed color. The net effect of UCR is that
less of the more expensive colored ink is required to reproduce
the desired colors in the image.
V
- Vignette:
- same as Gradient
- Vignette Threshold:
-
The term defines a %% value of change in the gradient which is considered as the same ink value for trapping decision purposes.
- Vignette Trapping:
-
Special case trapping of vignettes (gradients), which implies that these objects will be trapped half width spreading into the vignette and half width spreading into the adjacent objects.
W
X
Y
Z
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