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Graphic Communications
Copyright Goodheart-Willcox Co., Inc.
Color plays many important roles in our daily
lives. Aside from the aesthetic benefits to our
surroundings, the use of color on any medium can
greatly enhance communication. Color can be used
to grab attention, set a mood, or clarify images.
Colors should maintain consistency throughout
the production process. This is especially true
when so many products are recognized simply by
the colors on their labels or logos. To accomplish
this type of consistency, everyone from the graphic
designer to the press operator should have a basic
understanding of color.
Color Science
Without light, there is no color. Therefore, you
must understand a few principles of light before
understanding color science.
Principles of Light
The electromagnetic spectrum consists
of bands of different wavelengths, ranging from
radio waves to gamma rays, Figure 11-1. The
wavelengths are usually measured in nanometers
(nm). A nanometer is equal to one billionth of a
meter. Another unit used to measure the wavelength
of light is the Angstrom (Å). Ten Angstroms are
equal to 1 nm.
Our eyes can detect only a very small part of
the electromagnetic spectrum known as visible
light, which includes wavelengths ranging from
400 nm–770 nm. Each wavelength is seen as a
different color. Red light has the longest visible
wavelength (630 nm–770 nm) and violet has the
shortest (410 nm–440 nm).
Most light sources, including the sun, emit light
that appears to be white. However, that light is
Goodheart-Willcox Publisher
Figure 11-1. This illustration of the electromagnetic spectrum shows how small the range of visible light actually is. Each color
has its own wavelength or frequency.
Visible Invisible
Ultraviolet olet Ultrav U
X-Rays
Gamma
Rays
Infraredd Infrared d d
Microwave
THF/ TH H H
EHFH EH H
SHF UHF VHF HF MF LF ULF
0.001 nm 0.01 nm 0.1 nm 1 nm 10 nm 100 nm 1000 nm .01 mm .0.1 mm 1 mm 1 cm 10 cm 1 m 10 m 100 m 1 km 10 km 100 km 1000 km
Long wavelengths
Low frequency
Short wavelengths
High frequency