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A
Absorption
The dispersal and decreased transmission of visible
light in its interaction with matter, resulting in the change of
its color.
Appearance
The nature of objects as visual attributes, such as size, shape,
color, texture, glossiness, transparency and opacity.
Attribute
Colors are often described by their attributes of
hue, saturation or chroma, and lightness.
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B
Banding
Distinct pattern alterations, rather than a smooth transition of
colors or other effects in a gradient. Occurs in continuous tone
images when displayed using less than 24 bits of digital
information or if printing gradients without sufficient color
information.
Black
The absence of reflected light; the color that is produced when an
object absorbs all wavelengths from the light source.
When 100% of cyan, magenta and yellow are combined, the resultant
color should be black, but in reality produces a muddy gray or
brown. Therefore in four-color process printing, black is one of
the process inks.
The letter "K" is used to represent black in the CMYK
acronym to differentiate it from "B" for blue in RGB.
Brightness
The measurement of the reflective quality of a medium. Different
brightness levels can cause changes in the appearance of color on
the medium requiring adjustments in calibration to achieve optimum
result
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C
Calibration
Checking, adjusting and systematically standardizing the
graduations of a device.
Chroma
In visual perception, when an area appears saturated with a
particular color or hue. For example, a red apple is high in
chroma; pastel colors are low. Black, white and gray have no
chroma. Part of the color model, L*C*H or lightness, chroma, hue.
Also referred to as saturation.
CIE
Commission International de l'Eclairage or the International
Commission on Illumination, which is the main world institution
concerned with color and color measurement.
CMY
The subtractive primaries cyan, magenta and yellow.
Color
Calibration
Coordination of the color matching between two or more digital
devices by means by hardware or software.
Color
Curve
Visual mechanism in photo and graphics software to display color
measurements and make tonal changes in an image.
Color
Separation
Photographic or electronic process for creating patterns of plates
for each component of a color space. In printing, for example,
separating the cyan, magenta, yellow and black components of a
page image.
Color
Wheel
An arrangement of the visible spectrum's continuum of colors in a
circle fashion, that has complementary colors, such as red and
green, located opposite from each other.
Colorants
Materials used to create colors, such as dyes, pigments, toners
and phosphors
Colorimeter
Device that measures color values in relation to a specific set of
standards, such as CIE. Enables measurement of differences in
colors more precisely than the human eye.
Cyan
The "redless" process color. It absorbs all red
wavelengths and reflects all blue and green wavelengths of light.
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D
Delta-E
Unit of measurement of the perceivable difference in a color by
the human eye.
Densitometer
Device used to measure the density of light by means of its
absorption by a substrate or surface of paper or film. This is
achieved either by reflection or transmission.
Density
The ability of a material to absorb light. The
darker the material, the higher the density.
Digital
Printer
Printing device that translates digital data into hard copy
output.
Dithering
A process that simulates shades of gray or color variations by
differing sizes and shapes of pixel groups instead of an ordered
array of halftone dots. This reduces the contrast between dots of
different colors or shades and yields a more flowing, natural
impression.
Dot
Gain
The effect that is described when individual dots in a halftone
screen or other such patterns print out larger than their intended
size, resulting in a darkening of the image.
Dots
per Inch (DPI)
Measurement that describes the resolution of image files by
measuring the number of separate pixels represented either
horizontally or vertically in one square inch.
Dye
Colored chemical that dissolves completely in water or other
solvent; as opposed to pigments, which are insoluble.
Dye
Sublimation
Color printing technology that produces images by means of gaseous
dyes through a thermal printing driver.
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E
Enhanced Gamut Color
When precisely diluted process colors, usually cyan and magenta,
are used with CMYK to create more vibrant colors and a
continuous-tone effect.
Expanded
Gamut Color
When additional colors, usually green and orange, are printed with
CMYK to match a greater number of colors than produced by CMYK
alone.
F
Fluorescent Lamp
A glass tube filled with mercury gas and whose inside surface is
coated with phosphors. Once the gas is charged with electrical
current, radiation is produced which then energizes the phosphors
and causes them to glow.
Four-Color
Process
Printing or other imaging with combinations of the subtractive
primaries of cyan, magenta, yellow and black. These are deposited
as dots of different sizes, shapes and angles to create the
illusion of different colors.
G
Gamut
The range of colors that can be interpreted by a color model or
generated by a specific device.
Gamut
Compression
Also known as tonal-range compression. The coordinates of a color
space with a larger gamut are reduced to comply with the smaller
gamut of a destination color space. For example, the gamut of
photographic film is compressed for representation in the smaller
CMYK gamut in four-color process printing.
Gradation
The transition between two colors or between black and no color
which is created by mixing percentages of the dominant and
secondary color and then alternating them to produce the desired
effect.
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H
Halftone
The process of reproducing an image as a series of variable-sized
dots within a fixed grid.
Hexachrome
Color-matching system from Pantone, Inc. that is used with hi-fi
color systems and devices.
Hi-Fi
Color
Printing process that extends the tonal capabilities of most
printing presses by employing stochastic screening, six-color
printing and other techniques to expand the possible color gamut
beyond the traditional abilities of four-color processes.
Hue
The basic color of an object as defined by its angular position in
a cylindrical color space, or on a Color Wheel
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I
Inkjet
Printing process where liquid ink is propelled at a substrate,
such as paper or film, to form characters and graphics. There are
three kinds of inkjet printing: thermal, piezoelectric and phase
change.
Intensity
Saturation, or reflective light, in relation to visible
wavelengths of light. The reflectance of wavelengths at high
intensity generates high saturation or chroma.
L
Light
Electromagnetic radiation in the spectral range that is detectable
by the human eye (approximately 380 to 720 nm).
Light
Magenta/Light Cyan (LM-LC)
Muted or diluted forms of the two primary colors. When added to
CMYK these shades produce more variety in dot color and natural
continuous tone printing.
Lightness
The attribute that makes an area emit or reflect
more or less light. Also refers to the perception by which white
objects are distinguished from gray, and light from dark objects.
Luminance
Describes the brightness of an image.
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M
Magenta
The "greenless" process color. It absorbs all
wavelengths of green from light, while reflecting all red and blue
wavelengths.
N
Nanometer (Nm)
The measurement of wavelengths. Unit of length equal to 109
meters, or one millionth of a millimeter.
O
Opacity
Describes the resistance of light passing through a substrate.
P
PantoneÃ’
Matching System (PMS)
Unique numbering system for identifying colors created by
combinations of standard SWOP inks.
pH
A value that expresses the degree of acidity or basicity of a
solution.
Phase
Change Inkjet
Inkjet printing process employing the melting of solid ink plugs
and then spraying the droplets on media.
Piezo
Inkjet
Inkjet printing process that uses electric pulses from
piezoelectric crystals to stimulate and force ink through
inkjet nozzles onto substrates.
Pigment
Colorant that cannot be dissolved in a liquid. In inks, produces
sharper, darker images on a wider range of plain papers.
Pixel
A tiny picture element that contains red, green and blue
information for color rendering on a monitor or scanner. Pixels on
a screen are similar to dots of ink on paper. Monitor resolution
is described in terms of pixels-per-inch (ppi), while printer
resolution is measured in dots-per-inch (dpi).
Pixels
per Inch (PPI)
The number of pixels in a rastar image that occur in one line
along one inch. The greater the pixels, the higher the resolution.
Primary
Color
Colors that are the bases for other colors. In light, the primary
colors are red, green and blue (RGB). In color photographic
printing, they are cyan, magenta and yellow (CMY). Black or key
(K) is added as a fourth ink to CMY printing to produce denser,
truer blacks and clearer, sharper images.
Print
On Demand
Term for a variety of short-run publishing processes that include
copier technologies and direct-to-press applications.
Prism
Triangular-shaped glass or other transparent material through
which, when light is passed, its wavelengths refract into a
rainbow of colors. A demonstration that light is composed of
colors and indication of the arrangement of colors in the visible
spectrum.
Process
Color
Cyan, magenta, yellow and black combined to create a new color.
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R
Raster Image Processor (RIP)
Software and/or hardware used to convert digital printing to
information needed by a printer or other device to produce
finished output. This action is commonly called
"ripping" (a file).
Reflective
The ability of a surface to bounce back some or all of the
wavelengths of light that strikes it.
Resolution
The number of dots or samples-per-inch that a device is capable of
recognizing or producing.
RGB
The additive primary colors: red, green and blue.
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S
Saturation
Color attribute that expresses the degree of departure from the
neutral gray of the same lightness. Also known as chroma.
Sequence
The order in which inks are deposited by a printing device. In
CMYK inkjets the sequence is yellow, magenta, cyan and black.
Spectral
Curve
A visual representation of a color's spectral data as the color's
"fingerprint". A spectral curve is plotted on a grid
comprised of a vertical axis of the level of reflectance
intensity, and a horizontal axis describing the visible spectrum
of wavelengths. The percentage of reflected light at each interval
is plotted as points on a curve.
Spectral
Data
The most precise description of the color of an object. Since an
object's color appearance results from light being changed by it
and reflected to the viewer, spectral data describes how that
reflected light was changed. The percentage of reflected light is
measured at several intervals across its spectrum of wavelengths,
which is then visually represented as a spectral curve.
Spectrophotometer
An instrument that measures the characteristics of light that is
either reflected from or transmitted through an object.
Spectrum
The spatial arrangement of electromagnetic energy in accordance to
size of wavelength.
Spooler
The space where printing data is held in a computer's memory or
hard drive while queuing to a printing device.
Specifications
for Web Offset Printing (SWOP)
Formulations for inks used in web offset presses.
Standard
An established and approved reference against which instrument
measurements are evaluated.
Subtractive
primaries.
Cyan, magenta and yellow. The theoretical combination of the three
at 100% strength should produce black on white paper. Their
combination at varying intensities produces a gamut of colors.
Combining two primaries at 100% creates either the red, green or
blue additive primary. Cyan+magenta=blue. Cyan+yellow=green.
Magenta+yellow=red.
Surface
Tension
The forces of cohesion at the surface of a liquid which encourage
the tendency of a liquid to reduce its exposed surface to the
minimum area. Molecules within a liquid are attracted equally from
all sides, but those near the surface experience unequal
attractions and are thus drawn towards the center of the liquid
mass by this net force.
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T
Thermal Drop-on-Demand
Inkjet printing process where inks are heated in a chamber above
the print head to a temperature greater than their boiling point.
The heat alters and expands the characteristics of the ink, which
is then expelled through the head onto the substrate.
Tolerance
The acceptable difference between the known correct standard and a
set of measured samples. See
Delta Error.
V
Viscosity
The internal resistance to flow exhibited by a fluid.
Visible
Spectrum
The region in the electromagnetic spectrum between 380 and 720
nanometers. Wavelengths within this span produce color as viewed
by the human eye. Shorter wavelengths create violets, purples and
blues, while longer wavelengths result in oranges and reds.
W
Wavelength
Measurement of light as a component of electromagnetic waves. The
wavelength is the peak-to-peak distance between two adjacent
waves.
Y
Yellow
Pure yellow is the "blueless" color. It absorbs all
wavelengths of blue from
light, and reflects all red and green wavelengths.
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