After having the
confirmation and approval from our customers the jobs that have been completed
on prepress controls are ready for color separation process before printing.
Color separation is the separation of
the printing colors from the original full color job design. The printing
industry generates the colors from CMYK main colors. They are called; cyan,
magenta, yellow, black. Each of these colors in the set is posed over the plates.
The plates of each different color is separate and does the printing job by pressing on the
same surface to make the full color print.
With todays technology, the color
separation files are transfered directly to CTP (Computer to Plate) posing machines.
Also there may be some extra colors to be used besides Trichromatic Colors (the
CMYK Colors) to be able to emphasize any special color on the print. This color
will also be transferred to a separate plate like CMYK colors to go to the
print operation. We have to use a vector design or photo design software to be
able to prepare the file for this extra color and record it on a correct
Lightness or darkness of the color is
controlled by the grained surface of the aluminum special alloy CTP plates. The
grained surface consists of hemispherical, crater-like pits which will carry
the inks to the surface of cartonboard. The colors of CMYK system has a
technique to use angles to lay down side by side on the printed media to form
the vision which we see with full color. Each color should be arranged at a separate angle. The most
dominant color makes an angle of 45 degrees (this is usually black). The least
dominant color makes at least 0 degrees (this is usually yellow). Magenta and
Cyan is usually makes 15 or 75 degree angle to create different shades.
The method of the printing color dots
with angles is to help not to make any overlap to form different color tones. Our
eyes detect spots standing together side by side as if they are only one color.
Without this angle method, colors would overlap and makes a moire effect. Three
important terms used in color separations; DPI: Number of dots in 1 inch and
they are the transitions (tones) forming spots. Flood: Color tones formed without any
transtion. The print is done without using the dots. Lupe: The special magnifying
glass is used in color separations to check the print quality.
CEREN OFSET makes the color separation
directly to the CTP plates inhouse with LUSCHER CTP PLATE MACHINE XPOSE! Thermal
Model and KODAK CTP PROCESSING MACHINE used for this aim.