Additive Primaries: The colors red, green, and blue.
When white light is broken down into its component parts,
a rainbow (visible spectrum) is created. Dividing the rainbow
into about equal thirds results in red light, green light,
and blue light. By combining (adding) the three colors of
light together, white light is created.
Against the Grain: The direction across the grain.
Paper is used at right angles to its grain in a sheetfed
press. Paper is less strong and more apt to change size
against the grain.
Banding: A printing defect characterized by light
or dark lines in an image in the direction of the printing.
In the case of inkjet imaging it is caused by a jet or printhead
that is not properly aligned, inoperative, or incorrectly
indexed. The chemistry of the substrate surface can also
contribute to banding.
Bitmap: A series of individual dots or pixels that
define graphics. On a color or black-and-white system, a
bitmap defines a character or an image by turning each pixel
on or off. Each pixel must be recorded for a full image.
Paint programs use this format and are different than vector
graphics, which define graphics by points.
Brightness: 1. The amount of light being reflected
from a surface. 2. In a printed reproduction, the lightness
value regardless of the hue or saturation. Brightness is
affected by the reflectance of the paper. This is not called
CIE Color Space: a three dimensional mapping system
that is used to locate or plot the three color attributes
of lightness or darkness, red-green, or blue-yellow values.
Cockle: To wrinkle or pucker. Paper cockles or buckles
permanently when too much liquid is applied. Frequently
occurs when a volume of water-based ink is applied in a
Color: The visual sensation of human response to
seeing certain wavelengths of light. To see color, there
must be a light source illuminating objects that absorb
or reflect the light to the human eye. The color or colors
seen depend on the quality of the light source, the objects
light absorbability or reflectivity (the color of the object),
and the sensitivity of the human eye.
Color Balance: Maintaining the ration of cyan, magenta,
and yellow ink during printing. This will keep all color
hues consistent and produce a picture with the desired color,
one without an unwanted color cast or color bias.
Color Gamut: The complete range of hues and strengths
of colors that can be achieved with a given set of colorants
such as cyan, magenta, yellow, and black inks on a specific
Colorimeter: An instrument for measuring the tristimulus
values of color with a precise and defined response that
is similar to the human eye.
Color Matching System: 1. A color chart that has
been printed or stored in an electronic system and is used
to compare color samples, also called a color swatching
system. 2. A computer-based process that can measure a color
and formulate a new set of colorant amounts to reproduce
the measured color. The system can be used to mix special
Color Separation: The process of making a separate
electronic or photographic record of the amounts or each
process color of cyan, magenta, yellow, or black needed
to reproduce an original copy. The record may be a photographic
film made through the red, green, and blue separation filters
or a computer file. A set of four separations, cyan, magenta,
yellow, and black, are required to reproduce an original
color image, since each of the four process colors must
be represented. The separations may be made photographically
using traditional methods or digitally using electronic
scanners and computer programs. The original copy may be
a transparency (slide), reflection photographic print, drawing,
painting, or printed reproduction.
Color Space: A three-dimensional space or model
into which the three attributes of a color can be represented,
plotted, or recorded. These attributes are usually called
hue, value, and chroma.
Cyan: 1. The subtractive primary that appears blue-green
and absorbs red light. 2. A blue-green ink that is used
as one ink in the four-color printing process, sometimes
referred to as process blue.
CYMK: Abbreviation for cyan, yellow, magenta, and
black process colors or inks.
Density: The visual darkness of a material caused
by its capability to absorb or reflect the light illuminating
the material. Density is measured with a densitometer. Colored
materials are measured through their complimentary filters.
Density differences are sometimes called gray levels. As
density increases the amount of reflected or transmitted
light is reduced. The amount of light absorbed is inversely
proportional to the amount of light reflected from or transmitted
through the sample.
Dot: The term used to designate the mark or spot
on the paper or substrate.
Dot Gain: The apparent dot size increase from the
film to the printed reproduction.
Feathering: The bleeding of the ink into a non-printed
area usually due to capillary action of the fibers in the
Glossy: A shiny surface that reflects the specular
component of light away from the eye and, therefore, appears
Gray Scale: A narrow strip of paper containing an
orderly progression in definite steps or patches of gray
densities or printed halftone steps ranging in dot sizes
from zero to 100%. A gray scale is used to analyze and optimize
the contrast of black-and-white and colored reproductions.
The gray scale may be reflection-type made on photographic
paper, on a color proof, or printed on paper. On film, with
definite steps of either continuous tone or halftone dots,
it is called a step tablet. On film without definite steps,
it is a continuous wedge. On film with dots and definite
steps, it is a halftone scale. On a computer monitor, shades
of gray are created by varying the intensity of the screen's
pixels, rather than by using a combination of only black-and-white
pixels to produce shading. Printed, it is produced as a
narrow strip of paper, usually in the trim area of a job,
and used for analyzing printing characteristics.
Halftone: A negative or positive image made by photographing
an image through a screen so that the detail of the image
is reproduced with dots. The reproduction simulates the
different tones of the original by transforming them into
dots of varying sizes arranged in a grid pattern that has
a given frequency. For example, a 150 lines per inch halftone
would contain 150 rows and 150 columns of dots (22,500 in
a square inch) that could vary in size from zero percent
to 100 percent, also called screened negative or screened
positive. Halftones can also be generated electronically
from digital data.
Holdout: The ability of the paper to keep the ink
on the surface. The ink gloss is directly related to the
paper*s ability to hold the ink on the surface. Too much
holdout causes offset.
Hot Melt Ink: The class of inkjet inks that is solid
at room temperature and liquid at an elevated temperature.
Usually these inks are wax based and provide extremely high
color saturation, very sharp edge definition, and independence
from the characteristics of the printing substrates. The
disadvantage is the ink resides on the surface of the substrate
with little penetration unless there is a subsequent treatment.
This results in inks that can be chipped or rubbed off the
Hue: The attribute of color that designates its
dominant wavelength and distinguishes it from other colors.
Red is a different hue than green. While bright red and
dark red may have a different brightness or lightness, they
may be the same hue.
Imagesetter: A high-resolution laser output device
that writes onto photosensitive paper or film bitmap data
generated by an RIP.
Impulse inkjet: The branch of inkjet technology
where droplets are produced by a rapid pressure pulse created
in an ink chamber causing the expulsion of an ink droplet
through the orifice plate. In piezo-based impulse inkjet
systems this disturbance is caused by a rapid small change
in the volume of the ink chamber behind the orifice plate.
In thermal impulse technology this disturbance is created
by a rapidly growing and collapsing bubble due to ohmic
or electrical resistive heating. Sometimes erroneously referred
to as drop on demand type of inkjet printing.
Jet: A stream of fluid (ink) produced by discharge
through an orifice into free space.
Magenta: 1. The subtractive primary color that appears
bluish red and absorbs green light. 2. One ink in the four
-color printing process, sometimes referred to as process
Mask: A photographic film placed over an image in
order to modify the light that will pass through the image,
thereby changing a characteristic of the reproduction. This
task can also be handled electronically on digital prepress
systems. There are a variety of masks, including area masks,
outline masks and unsharp masks.
Matte: A dull or rough surface, lacking gloss or
luster, such that more light is reflected to the eye and
colors appear less dense.
Metameric color: A color that changes its perceived
hue under different illumination. For example, it is possible
to have two color samples match under tungsten (incandescent)
illumination and not match when viewed in sunlight.
Monochrome: One color; refers to black and white
Mottle: Uneven print density or uneven color. A
defect in matrix color printing because of a lack of dot
placement accuracy or variable dot density. Most readily
apparent in areas of solid printing.
Offset: 1. A type of conventional (non-demand type)
printing employing a plate cylinder with areas of hydrophobic,
(water-repulsive) and hydrophilic (water-compatible) areas.
The hydrophobic areas will then attract oil-based printing
inks. This image is also transferred to a blanket cylinder,
which then contacts the surface to be printed. Also known
as lithography. 2. A defect in a printing system where a
printed image is transferred onto the back of another printed
sheet of paper because the ink is not dried before the second
paper contacted it.
Opacity: The property of paper that minimizes the
"show-through" of printing from the back side or the next
Orifice: A hole or aperture without appreciable
length. In most cases this is the technically correct term
for the hole employed in inkjet printing systems.
Overprint: To print dots of one process color ink
over dots of another process color ink to produce overprint
colors or secondary colors such as red, green and blue.
Piezo Printing: The type of inkjet printing in which
an electrical signal causes a piece of crystal in the printing
nozzle to deflect, thereby ejecting the ink droplet from
Pixel: Acronym for picture element, the smallest
picture sample that can be sensed, manipulated or output
by a digital system. In a color system, each pixel is represented
either by cyan, magenta, yellow and black values, or red,
green and blue values.
Primary Colors: The colorants of a system that are
used to print the colors for the entire reproduction. Cyan,
magenta and yellow are subtractive primary colors, while
red, green and blue are additive primary colors.
Prime: The act of initially introducing ink to a
inkjet printhead and forcing ink out of the orifices to
expel air from the chamber or the ink manifold.
Process Color: A printed color or image that is
rendered by a combination of three primary colors. In theory,
all colors of the spectrum can be reproduced by combining
different amounts of three primary colors. The three primary
colors in the subtractive system are cyan, magenta, and
yellow. Because of paper defects, show through and variations
in illuminating light, it is very difficult in practice
to have a complete color gamut from the three primaries.
Additionally, to make black by combining the three primaries
is very expensive because it utilizes so much ink. Therefore,
black is frequently added as a fourth ink component. This
process is called under-cutting.
Resolution: In matrix printing, the number of dots
or picture elements (pixels) per unit length. Frequently,
the vertical and horizontal resolution is the same. Expressed
as dots per inch in the English system and dots per centimeter
in the metric system.
RIP: Abbreviation for raster image processor, a
software program or computer that determines what value
each pixel of a final output page bitmap should have based
on commands from the page description language.
Saturation: the attribute of a color that describes
its degree of strength and its departure from a gray with
the same lightness.
Sharpen: To make halftone printing dots smaller.
Using negative separations, sharpening is accomplished with
dot etching. Over exposure will also sharpen the negative
films. When positive working plates are made using positive
transparencies, sharpening happens automatically and the
size of the printing dots are reduced by 5%. This sharpening
is called negative dot gain.
Spectrum: The range of colors visible when white
light is passed through a prism. The prism divides the white
light into wavelengths from short to long.
Spot Color: Localized color assigned to a graphic
or block of text, prepared with a color break and printed
without the use of color separations. Usually process color
is not assigned to the spot color areas. Spot color is frequently
printed with non-process color inks, although process inks
can be used as well.
Substrate: Any material that can be printed on,
such as paper, film, plastic, fabric, cellophane, or steel.
Subtractive Primaries: The process ink colors, cyan,
magenta, and yellow. Each absorbs or subtracts its complimentary
color, red, green, or blue, from the light reflecting off
the paper. Cyan, magenta and yellow printed together produce
a three-color black, which is slightly brownish because
of the unwanted hue error of the inks.
Tack: The amount of stickiness in printing inks
that makes them print while minimizing dot gain.
TIFF: An acronym for Tag Image File Format, a standard
file format that was developed by Aldus Corporation for
bitmap or raster graphics, usually for scanned images. TIFF
can handle a variety of image data, from 8-bit black and
white images, to 24-bit color RGB (Red, Green, Blue) or
CYMK images. Vector graphics are usually stored in PICT
or EPS (Encapsulated PostScript) format.
Tone: The character of a color, its quality or lightness.
Used as a verb (to tone) means to change or modify a color.
Trapping: 1. Adjoining colors overlapped by a row
or two of halftone dots to minimize the effect of misregister.
Without trapping a fine white line would appear between
two color images during the printing of process color. 2.
The ability of an ink to print onto another ink. One hundred
percent trapping occurs when the same amount of ink will
print on the first ink as on the unprinted substrate. More
frequently undertrapping occurs, because one wet ink will
not adhere properly when applied to another wet layer of
ink. Ink trapping is controlled by adjusting tack.
White Light: Illumination, such as sunlight, composed
of all the colors of light in the visible spectrum. The
visible spectrum components can be seen in a rainbow or
in sunlight shining through a prism.
WYSIWYG: An acronym for "what you see is what you
get." The term is used in several situations, such as when
a color proof is shown to the customer. The person presenting
the proof assures the customer that what you see is what
the press will produce. Or, in desktop publishing, the term
is used to refer to the ability of desktop computers to
display on their monitors a reasonable representation of
what will appear on the printed page.
Yellow: 1. The subtractive primary color that appears
yellow and absorbs blue light. 2. One of the four-color
process inks made from the organic pigment, diarylide yellow,
formerly called benzidine yellow.
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