Offset is traditionally used for printing the
same design in huge numbers.
This requires an
of the design which can be converted to a Positive . This in turn is exposed on
to a printing
plate, one plate for each of the four basic
colours of Cyan, Magenta, Yellow and Black and the extras for special colours
like silver, gold etc if any.
On the Printing Press, there are separate
or sections for different colours and one unit is meant for a specific colour
only. As a result the design gets printed on paper one colour at a time, in a
sequence. The number of colours a machine can handle in one run depends on the
number of units it has i.e., a two colour press prints in two colours in one
consistency of colours
is largely dependent on the positives exposed onto the plates. These encode the
percentages in which the different colours are transferred on to the paper in
the different units. However, the printer physically checks the flow of inks to
ensure consistency in colour on all the printed sheets.
On these Printing Presses only
of a sheet is printed at a time. It must be then allowed to dry before it can
be printed on the reverse. If that's not required, it still needs to dry before
it is cut to size. Offset printing gives a
remarkable replica of the design , it has
great clarity, sharpness and brightness. It is the best method for printing on
paper, and becomes the most
economical as the volumes increase .
Screen Printing :
Screen Printing is conventionally used for printing the same
design in small numbers. Screen Printing
that is photographed to produce a
This positive is exposed onto a fine
using a simple tube light or at times just the sun's rays. This process allows
the silk to be porous in different places based again on the number of colours
and the design.
The paper is placed in a marked out area on a table and inks are placed one at
a time on the screen. The inks are "squeezed" out by running a flat wooden
piece over the screen. Here the paper needs to
dry even between colours
and not just between the different sides of the paper. As is clear this method
much slower than Offset printing!
Another drawback is the
lack of clarity and sharpness
of the images in this method therefore it is better suited for
rather than images.
The consistency in colour largely depends not only on the exposed screen but
also the judgement of the printer.
of Screen Printing :
- This method is ideally suited for printing on Fabrics, Ceramics, Plastics,
- It is mostly suited for texts rather than images.
- Screen printing has been widely used for low volume printing; as quantity
increases it becomes less economical in time as well as in