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Commercial
Colour Printing: Part 1 |
Part 2
Contributor:
Bob Swinbank
Bob Swinbank of Cardinal Publicity provides
an accessible overview of the printing process in
this two page extended article by explaining the
fundamentals of The Four Colour Process,
Offset Lithography,
and The Five Stages
of Print Production.
The
Four Colour Process
The most common system for producing full colour
print.
The vast majority of magazines and colour books
are produced using four-colour process. Originally
the artwork and originals were separated photographically
using filters to produce four printing plates. Today
the separation is carried out digitally.
The four ink colours are Cyan (Blue), Magenta (Red),Yellow
and Black - often referred to as CMYK. Because the
inks used are translucent, they can be overprinted
and combined in a variety of different proportions
to produce a wide range of colours.
Theoretically it is possible to produce an adequate
range of colours using just Cyan, Magenta and Yellow.
Indeed for a time three Colour Process was a viable
option. However, in practice much better results
are achieved with the addition of black. The black
plate is used to strengthen the shadow areas and
reduce the amount of CMY inks required.
Although the range of colours which can be achieved
is adequate for most jobs the process has its limitations.
It is important to remember that many colours which
are available as special inks have no close equivalent
in four colour process. In some cases it may be
necessary to print a fifth plate in order to match,
for example, a particularly difficult company logo
colour. The additional cost of this is normally
prohibitive and the necessity should be avoided
at the design stage.
It is not unusual, where an elaborate effect is
required, to print in six or more colours. There
are presses which are capable of printing eight
different plates in a single run through the machine.
Commercial
Colour Printing: Part 1 | Part
2
This article has been reproduced under permission
and may not be copied without explicit consent from
the author Bob Swingbank © 2003.
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