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All Zebra
plastic card printers feature the same basic printing operations;
dye sublimation and/or thermal transfer printing. Both techniques
involve a ribbon being heated as it passes under a thermal print
head. The difference is that thermal transfer ribbons heat up and
transfer ink onto the plastic card, and dye sublimation ribbons
heat up and undergo a chemical change process that turns the ink
into a gaseous state which then permeates the plastic card.
The ribbon
used in color dye sublimation printing is divided into three
separate color panels Yellow, Magenta, and Cyan (see Figure 1).
This configuration is referred to as YMC.
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yellow
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magenta
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cyan
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yellow
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magenta
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cyan
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(fig.1)
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These
three colors are the primary colors used in printing to
produce all other colors including black.
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The dye from
the ribbon is applied to the plastic card via a multi-pass
operation. This means the card will pass under the print head
once for each of the three colored ribbon panels - applying each
color separately.
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yellow
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yellow
& magenta
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yellow,
magenta & cyan
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The
term Dye Sublimation is also referred to as Dye Diffusion. When
the Dye on the ribbon is heated by the print head it is
transformed from a solid to a gas and diffused onto the plastic
card (the card is specially coated to absorb the color dye). The
hotter the elements in the print head, the more dye is converted
to a gas and absorbed into the plastic card. At 300dpi the picture
quality and continuous color tones produced by a dye sublimation
printer outperforms most laser or ink jet printers with higher
resolutions
The
advantage of dye sublimation is the millions of colors that can be
created. The colors result from a combination of the panels on the
ribbon. By combining these colors and varying the intensity of the
heat, providing various shades of each color, you are virtually
unlimited in your color selection.
Thermal
Transfer differs from Dye Sublimation in that Thermal Transfer
uses Ink rather than Dye. Both Dye Sublimation and Thermal Ink
(sometimes refered to as Resin) can be combined in one ribbon (see
Figure 2). This ribbon is referred to as a YMCK Ribbon. The letter
"K" is the designator for the color black in the
printing industry.
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yellow
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magenta
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cyan
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black
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yellow |
magenta |
cyan
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black
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2) |
Why
do you need a separate black panel, when you can create
black by mixing the three basic YMC colors together? |
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The
answer to this question is simple. When black is created by mixing
the YMC colors together it creates what is referred to as
"Composite Black." Composite Black typically looks muddy
or has a grayish tint when compared to Thermal Transfer (TT or
resin) black. Composite Black is not recommended for printing bar
codes since combining the three colors together does not produce
the sharp edge many scanners require (this is invisible to the
naked eye but can be observed under magnification). Composite
Black is also invisible to IR scanners since there is no carbon in
the dye. Since you may not know what type of scanner will be used,
the rule is to always use TT (resin) black to print bar codes.
All Zebra printers are capable of printing in monochrome using a
single color ribbon. These ribbons are less expensive than full
color multi-panel ribbons and can be either dye or ink (thermal
transfer). The most commonly used monochrome ribbon is
"Black" but there are several other colors available
including; Red, Green, Blue, and Yellow.
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| Monochrome |
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3) |
Dye
Sublimation ribbons are preferred when you are printing
pictures, since they can produce many shades of gray for a
smoother look and a better picture quality. A resin black
picture normally uses a dithered gray scale (gray made from a
combination of pixels which limits the number of shades),
producing a coarser, grainy look to the image.
Thermal
Transfer (resin) ribbons should be used to print text, bar codes
or single color graphics such as simple logos. Black monochrome
ribbons are represented by the letter "K" followed by
a lower case "r or d", (Kr or Kd). The "r"
designates a Thermal Transfer ribbon with resin ink. The
"d" designates a dye sublimation ribbon
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