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How do
inkjet
printers
work?: |
An inkjet
printer is
any
printer
that
places
extremely
small
droplets
of ink
onto paper
to create
an image.
Inkjet
printers
are
non-impact
meaning
that the
print-head
mechanism
does not
touch the
paper
during
printing.
Inkjet
printer
droplets
have
certain
common
characteristics:
-
The dots
are
extremely
small
(usually
50 to 60
microns
in
diameter)
-
The dots
are
positioned
very
precisely,
with
resolutions
of up to
1440x720
dots per
inch
(dpi).
-
The dots
can have
different
colors
combined
together
to
create
photo-quality
images.
There are
two
commonly
used
inkjet
printing
technologies
used by
manufacturers:
Thermal
bubble
- Used by
manufacturers
such as
Canon and
Hewlett
Packard,
this
method is
commonly
referred
to as
bubble
jet. In a
thermal
inkjet
printer,
tiny
resistors
create
heat, and
this heat
vaporizes
ink to
create a
bubble. As
the bubble
expands,
some of
the ink is
pushed out
of a
nozzle
onto the
paper.
When the
bubble
"pops"
(collapses),
a vacuum
is
created.
This pulls
more ink
into the
print head
from the
cartridge.
A typical
bubble jet
print head
has 300 or
600 tiny
nozzles,
and all of
them can
fire a
droplet
simultaneously.
Piezo
Electric
- Patented
by Epson,
this
technology
uses piezo
crystals.
A crystal
is located
at the
back of
the ink
reservoir
of each
nozzle.
The
crystal
receives a
tiny
electric
charge
that
causes it
to
vibrate.
When the
crystal
vibrates
inward, it
forces a
tiny
amount of
ink out of
the
nozzle.
When it
vibrates
out, it
pulls some
more ink
into the
reservoir
to replace
the ink
sprayed
out. |
How do
laser
printers
work?: |
Please
remember
that all
our
dustjackets
are
created on
paper
specially
manufactured
for
industrial
laser
printers
and
thermal
color
copiers.
Inkjet
printers
have
different
considerations
since
static
charge is
used to
apply the
toner.
After
comparative
testing,
we have
chosen
Xerox
Digital
Color
Expressions
for its
superior
color
quality.
Importantly,
this paper
is
acid-free
and
chlorine-free
to ensure
long-life
archival
preservation
and color
retention.
This is a
very
expensive
paper
though
[factored
into our
jacket
pricing]
typically
costing
$15 per
ream vs.
$2/$3 per
ream of
typical
office
paper --
essentially
5 to 7
times the
cost of
typical
copy
paper. |
Which
printing
technology
is better
- inkjet
or laser?: |
So why get
a laser
printer
rather
than a
cheaper
inkjet
printer?
The main
advantages
of laser
printers
are speed,
precision
and
economy. A
laser can
move very
quickly,
so it can
"write"
with much
greater
speed than
an ink
jet. And
because
the laser
beam has
an
unvarying
diameter,
it can
draw more
precisely,
without
spilling
any excess
ink. Laser
printers
tend to be
more
expensive
than
inkjet
printers,
but it
doesn't
cost as
much to
keep them
running
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What does
paper
brightness
mean?: |
The
brightness
of a paper
is
normally
determined
by how
rough the
surface of
the paper
is. A
course or
rough
paper will
scatter
light in
several
directions,
whereas a
smooth
paper will
reflect
more of
the light
back in
the same
direction.
This makes
the paper
appear
brighter,
which in
turn makes
any image
on the
paper
appear
brighter.
You can
see this
yourself
by
comparing
a photo in
a
newspaper
with a
photo in a
magazine.
The smooth
paper of
the
magazine
page
reflects
light back
to your
eye much
better
than the
rough
texture of
the
newspaper.
Any paper
that is
listed as
being
bright is
generally
a
smoother-than-normal
paper.
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How does
absorption
affect
image
quality?: |
A key
factor in
image
quality is
absorption.
When the
ink is
sprayed
onto the
paper, it
should
stay in a
tight,
symmetrical
dot. The
ink should
not be
absorbed
too much
into the
paper. If
that
happens,
the dot
will begin
to
feather.
This means
that it
will
spread out
in an
irregular
fashion to
cover a
slightly
larger
area than
the
printer
expects it
to. The
result is
an page
that looks
somewhat
fuzzy,
particularly
at the
edges of
objects
and text.
As stated,
feathering
is caused
by the
paper
absorbing
the ink.
To combat
this,
high-quality
inkjet
paper is
coated
with a
waxy film
that keeps
the ink on
the
surface of
the paper.
Coated
paper
normally
yields a
dramatically
better
print than
other
paper. The
low
absorption
of coated
paper is
key to the
high
resolution
capabilities
of many of
today's
inkjet
printers.
For
example, a
typical
Epson
inkjet
printer
can print
at a
resolution
of up to
720x720
dpi on
standard
paper.
With
coated
paper, the
resolution
increases
to
1440x720
dpi. The
reason is
that the
printer
can
actually
shift the
paper
slightly
and add a
second row
of dots
for every
normal
row,
knowing
that the
image will
not
feather
and cause
the dots
to blur
together.
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